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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

BY
GHARLES D. WALCOTT

“*BVERY MAN 1S A VALUABLE MEMBER OF SOCIETY WHO, BY HIS OBSERVATIONS, RESEARCHES,

AND EXPERIMENTS, PROCURES KNOWLEDGE FOR MEN’’—SMITHSON

(PUBLICATION 2790)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
1924

<
°

The Lord Baltimore (Press
BALTIMORE, MD., U. S. Ae

The present series, entitled ‘ Smithsonian Miscellaneous. Collec-
tions,” is intended to embrace all the octavo publications of the
Institution, except the Annual Report. Its scope is not limited,
and the volumes thus far issued relate to nearly every branch of
science. Among these various subjects zoology, bibliography, geology,
mineralogy, and anthropology have predominated.

The Institution also publishes a quarto series entitled ‘‘ Smith-
sonian Contributions to Knowledge.” It consists of memoirs based
on extended original investigations, which have resulted in important
additions to knowledge.

CHAREES: D: WALCOTT,
Secretary of the Smithsonian Institution. ~

(iii)

CONTENTS

. WatcotT, CHARLES D. Nomenclature of Some Cambrian
Waramlaran, Mortimat wore occurs o.oo sb csdels aes wis whee wk
Published May 9, 1917. Pp. [Title] + 1-8. (Publ. No. 2444.)

. Watcott, CHarLtes D. The Albertella Fauna in British
(alumina anid. Mioitamysina sets, oso sleds x eos ead o's as
May 9, 1917. Pp. [Title] + 9-59, pls. 1-7. (Publ. No. 2445.)

. Waccort, CuHarLtEs D. Fauna of the Mount Whyte For-
ES ETC) EG aa eR len Os a A rr

September 26, 1917. Pp. [Title] + 61-114, pls. 8-13. (Publ. No.
2480.)

PevaLcorr Cranes 1D). Appendases of Trilobites::.......
December, 1918. Pp. [Title] + 115-216, pls. 14-42, text figs. 1-3.
(Publ. No. 2523.)

. Watcortt, Cuartes D. Middle Cambrian Algae...........

December 26, 1919. Pp. [Title] + 217-260, pls. 43-59. (Publ.
No. 2542.)

. WatcotT, CHarLes D. Middle Cambrian Spongiae........

April 2, 1920. Pp. [Title] + 261-364, pls. 60-90, text figs. 4-10.
(Publ. No. 2580.)

. Watcotrt, CHARLES D. Notes on the Structure of Neolenus.

December 20, 1921. Pp. [Title] + 365-456, pls. 91-105, text figs.
11-23. (Publ. No. 2584.)

. Watcott, CHARLES D. Nomenclature of Some Post Cam-
brian and Cambrian Cordilleran Formations (2).....

March 5, 1923. Pp. [Title] + 457-476, text fig. 24. (Publ. No.
2673.)

. Watcort, CHarLes D. Cambrian and Ozarkian Brachiopoda,
Ozarkian Cephalopoda and Notostraca..............

June 3, 1924. Pp. [Title] + 477-554, pls. 106-126. (Publ. No.
2753.)

(v)

PAGE

115

217

261

365

457

477

ILLUSTRATIONS

PLATES

FACE PAGE
i; Fanoramic: view of Mount..Bosworth.:. 0... 5.....6...4% 12
peivoss, Wace cirque and. ropes; Peden ci. '. 22%. dss fee tected, 14
3. Profile view of north cliff of Ross Lake Mountain........ 15

4-7. Illustrations of fauna of Ross Lake and Gordon shales

and of the limestones of the Ptarmigan and Chetang
OULIO BAC Rap Pe Recital 52-58
SOME FA LAF CIUCOCY OLN UER sie arse ire io elvan. oe 6 wae vi @ 104
aconumenoonus and, VMesonacis 22 2... 2c vnc este es ak sss 106

10. Corynexochus, Micromitra, Acrothele, Wuimanella, and
OME ee os Sw 2 Cae Pines Meas tists sen s/ei8 108

11. Crepicephalus, Ptychoparia, Olenopsis, Dorypyge, and
ONAL AC oP RE gee Cac oe ea ot ae 110
C8, PSR 2007017 ot rs i822 112
ie Agraulas, Olenopsis, and’ PiyChoparia f.. wie wee eb eee ss 114
MEM NICOLERITS ANG IK UOLC NIMs? a cara iene Glade Siarkce cd ale, Seid vind oial sie» 180
Dyevecienus serratus (RoOmmMPer ies. oe 3... oe os i i 181
16. Cephalic appendages of Neolenus serratus (Rominger)... 182
i7. Nealenus serratus (Romingen) 7 sci ..c a sos 0. i votes a 183
ie. WVeoienus serratus (ROMINgEr)).a..o oe ese ss ots, Soe 184
Boe eal eniis serratus (ROMINA Ei ec. Evie oc wis%s Ghee ayepere s,s sis 0) 185
20. Branchiae—Neolenus serratus (Rominger)............. 186
Peaivesaparia. and -N Cole se ams seksy othe tins reins one'de sees © 187
22. Neolenus serratus (Rominger), illustrating exopodites.... 188
BPP OLEIIES SONPOLUS | INOMMINSETY miso soe as 'g a 0s .n since acs’s os 189
AME OIC UE Siecle lcd, ssc: x ¢ia' bo ge Rap Des 8 PIE eka ie sor teoe alae ate 190
AG ae SOreUs MAINS LOCKE jae kk tee sfa\s «x Morereiar Joana's: IQI
26. Sections of trilobites, Calymene and Ceraurus........... 193
27. Sections of trilobites, Ceraurus, Calymene, wire spirals... 195
Boum Ordawician. tilopilesmipen a ce eee el SES a ke ee ea 197
ao; Appendases of 7 riarivrus decks Gre@is: se... ee cee we 199
30. Triarthrus becki Green..... ithe Een Ole Seas Oe ne ae 201

31. Restoration of ventral surface of Neolenus serratus
STEIN) 1 2Cy ys Sue Do oe ae 203
32. Restoration of ventral side of Triarthrus becki Green..... 204
33. Restoration of ventral side of Calymene senaria Conrad... 205

(vii)

Vill ILLUSTRATIONS

FACE PAGE

34. Cambrian and Ordovician trilobites with ventral appen-
dages. Transverse diagrammatic sections............. 206

35. Diagrammatic sketches of thoracic limbs, trilobites and
FECEHE CHUISHe COANIS st Sr Bovaate Wie vai atale cet) eae is fe revat alata ne 207
36.’ Crustacean! limb, Neolenussand: Abus. : os. .oun eee 208
a7. Trilobite tracks and stralsos > to52' 2s 2.2 tae ae og epee ee 209
38. ‘Teilobite*tracks and trails. 2 sexs 5 ote. ce eee 212
39. *Frilabite*tracks andatralls -. 30-06 sce rac Sere ae eee 213
40, Tilobite tracksfand: trails< 2.2 sca. ieee eee 214
41. ‘Inlobite;tracks*and trails... <a) ccletreiaite eo toi oe 215
42. Trilobite tracks. and annelid: trails 21.4. s.r 216
43, 44,45. Morania continens Walcott.............. 244, 245, 246

46. Nostoc commune Vaucher, N. verrucosum (Linn.)
Vaucher, N. parmelioides Kutzing, and Anabaena varia-
Dilts IR Ui zine s,s <2 ahh tele iote eee eee eee 247
47. Morania costellifera Walcott and M. elongata Walcott.... 248
48. Morania fragmenta Walcott and M. ? globosa Walcott.... 249
49. Morania frondosa Walcott and Morania species anderae!
mined

bots a ee EMR

50, Worama parasitica Walcott 02 See ae ee 251

51. Cladophora gracilis (Griffiths) Kutzing and Dumontia
ilsformis:.(ciuds,)) Greville 2 eerie aerate a ee nites 252

52. Marpolia spissa Walcott and Moramia reticulata Walcott.. 253
53. Nostoc sphaericum Vaucher, N. pruniforme (Linn.)

Agardh, and Dasya gibbesn: Harvey... ..-. 0 eee 254
54. Yuknessia simplex Walcott and Waputikia ramosa Walcott 255
55. Marpolia aequalis Walcott, Wahpia mimica Walcott, Dalyia

mitens Walcott, and D. racemata Walcott............. 256
So: Dalya racemata Walcott. +... 2<2 4 sae 257
57. Wahpia insolens Walcott, W. virgata Walcott, and Bos-
worthia svmulans” Walcott, avin. 0es eee poe ee 258
58. Bosworthia simulans Walcott, B. gyges Walcott, Morania
confluens Walcott, and Morania and trilobites........ 259
59. Sphaerocodium ? praecursor Walcott and S. ? cambria
Wane 05 6 Gi atvesatobsg ei es sheeted seats isis Sole eee 260
60, 61. Halichondrites: elassa..Waltott')..224 7. <a ees 334, 335
62, 63.) \Tupomaciimenta Waleott? \)... 4s. nit. se eee 336, 337
64. Tuponia flexilis intermedia Walcott and Tupoma belli-
lineata. Walcot® ooo oe ic. ee de VLG ghee eee ea 338

65: TFuponia fers \WValeatts (Reka. te eee eee 339

ILLUSTRATIONS ix

F FACE PAGE

66, 67,.48.. Wapita grandis Walcott... ... 60. 05. eee 340, 341, 342

SOE ORIOL CRA EN (Glo, 7 Dee ea a 343

Wah iL Gaels WCLICAbula> WV AlCOE? tis ies tet See ete eas be eae 344
71. Hazelia obscura Walcott, Hazelia ? grandis Walcott, and

arena noauljerd: VWaAlcOtt.)5.% uc tidy tne ess ss 345

72. Sentinelia draco Walcott, and Corralia undulata Walcott,
Hazelia conferta Walcott, and Choia carteri Walcott... 346

73. Choia carteri Walcott and Choia ridleyt Walcott......... 347
Pape mommerialent: WW AlCOLEs 214 cy) cele a oo. 2e vy odo = Case tere 348
75. Choia utahensis Walcott and Choia carteri Walcott....... 349
76. Choia hinder (Dawson), Hagelia palmata Walcott, and
iigmpronia bowerbankis Walcott: «i> < 0:6. << ese sss 350
77,78 Hamptoma bowerbankt Walcott.............006- 351, 352

79. Pirania muricata Walcott and Protospongia erixo Walcott. 353
80. Protospongia fenestrata Salter and Protospongia hicksi
Maer ass) 4,22": AR MER Sie ala we alte a iw aS 354
81. Diagoniella hindei Walcott and Vauxia dignata Walcott.. 355
82. Vausxia bellula Walcott and Vausxia gracilenta Walcott.... 356

ea euaunormciionta \WalcOtioamascsie swiss ss sls Sinsise Se aie os 357
Pa metarden sar Walcott.!.-s sess acces k Paw oes REE a 358
Boe aamerio Gs CONG VWalcOttretaict v-\orcicts occiels iy sweet viele s 359

86. Eiffelia globosa Walcott and Chancelloria eros Walcott.... 360
87. Chancelloria libo Walcott, Chancelloria drusilla Walcott,
Chancelloria yorkensis Walcott, and Takakkawia lineata

Me G EM ses) = $5: « /<.c x Shenae MRNMEnS SNR Girajoheieis = Slave ayes +0» 361
omcnanarilora crs, VWalcOtiawew sie «civ stzj-) se 018 oie te locos 362
89. Kiwetinokia utahensis Walcott and Kiwetinokia spiralis

WIE OLE: eis oc «0 5.x PON no os SER aN A RE oe 363
90. Tuponia lineata Walcott, Hazelia delicatula Walcott, and

EAOselianmamimularg NV AIC OLE nas wero eid ew ae nies bes we 364
g1. Limbs of Neolenus, Ceraurus, and Calymene............ 434
G2, Mxepadites and eptpadites.Of W20lenus .. ss cs se eens 435
poop ental IN COUCHES! SCHTIUN Sita. 6 sleie%s tra) ths-siwie's sle)F ac oes 436
94. Restoration of ventral surface of Neolenus serratus

(Rominger) ne Hy Ai GG cic a: ate ce eae 437
Ge ee PeiiONS 1 O MiClODLEES, - accie: cies orice la ciate wie 6 sls Sas 438, 440
Dre secuons: of trilobites (Exopodites) 02.66. c sce ea ene 442
Pee TOS SeeHOTS Oki TOMILeESs Sits e clarete ale eal x ate «eels 444-452
104. Sections of trilobites. Appendages of Triarthrus......... 454

Me ECHONSOT PIMODILES (2 ai.4 x... bi anle a en's ob 'e lo See Se ose o\6 456

x ILLUSTRATIONS
FACE PAGE
106. Brachiopoda:, MicramitrarOboluscc. 2.62 a2 ee eee 534
107. e ODGUS 75 5) os che Rae Che TEAC ee ee 535
108. . Obalus, Linguleila.- 32522750, dae 536
109. ‘: Lingulella, Lingulepsis, Acrotreta, Nisusia .. 537
TIO. NESS I - i= ate g o9 hen Rn eg = ee 538
ip ps Nisusia, Wimanella, Billingsella, Protorthis. 539
112. 3 Billingsella-E oortlis” =. 8.2.4 <a dee eee 540
Li. 4 Provortiis EL Oorthis.=... won ee eee 541
II4. if FLOOTWMES Ue Ten Share Soa ee ee 542
LLG * EOorthis, -Finkelmbargia nets ccl tens ae ee 543
116. ci BOOrts © ov siaeie Bead, Da oat ee 544
iv Eoorthts.SVnuropna..sccae ants eecle ere 545 -
LTO LEO Syntroplua, Huenclla,.... 2. 22<s eee ee 546, 547
120: ‘i Finenela 0020 cae ine aici eee 548
T20: 3 Balhingsella, Obolus 2-3 125 eee eee 549
122. # Lingulella, Acrothyra >. 2.5 550
123: 4 Lingulella, Billingsella. Novaya Zemlya Bra-
chiopods® 4.2.) Spates. 3 ee 551
124. x Billingsella-Eoorthis. Novaya Zemlya Bra-
ChiOpOds . <:<.ser. Sresteet A Se Ect ate ane 552
125. ve Huenella. Novaya Zemlya Brachiopods.... 553
126. Cephalopoda, Notostraca. Ozomia, Endoceras, Ellesmero-
COVES’ WSs ciicaye is A Gin says asta gee Te ee ee 554
TEXT FIGURES
PAGE
Fic. 1. Anaspides tasmanie G. M. Thomson................ 171
2. Koonunga cursor Sayce.... feck jo whale te anda abe rege ae 171
2. Paranaspideslacusiris Smith... 225 0s eee 172
4, 4a. Piramia -muricata Walcott - 2 sc ccs 2 ats ore wre 299
5,6. Protospongia mononema Dawson..............-.. 303
7. Diagomella cyaithiforms Dawson... ..c vest ae ee 309
8, 8a. Kiwetinokia metissica (Dawson)................ 316
9, Vauaia gracilenia Walcott... Me Duc face ee 319
10; Eriteha. globosa-W aleottxc)s 58. citer ee oe 324
II, 12,13, 14. Diagrammatic views of structure of Neolenus
serratus ( Rominget): 3c: << see. eee 371-375
ES. Lambs Of W.olenuss « tetecs0/ ons «eee eee ee 383

16. Outline of transverse section of thorax of Ceraurus... 384
17, 17a. Outlines of portion of exopodite of Calymene.... 410
18, .Photogtaph of wire. spiralse. 2 ...02..Gk 22 ae ee 411
19, 19a. Outlines of portion of exopodite of Triarthrus... 411

20.

Zils

22.

23)
24.

ILLUSTRATIONS Xi

FACE PAGE

Outline of restoration of fimbriated epipodite of
NOTES a FIN ik AN to a ale seine «6 clabun ss os 419

Thoracic limb of Neolenus, Ceraurus, Calymene, and
DG ARCHOS Ue ante RO le rene oth ake Gee d Sis aiacs Ud oa) «oye 421

Diagrammatic outline of a coxopodite with cross sec-
tions sndicated:> ac vaunn-s Bint aD Oye ee 422
Exopodite of Triarthrus becki Conrad............... 423
Cambrian-Ozarkian-Ordovician correlation Table..... 470

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 1

CAMBRKIAN
GEOLOGY AND PALEONTOLOGY

No. 1. NOMENCLATURE OF SOME CAMBRIAN
CORDILLERAN FORMATIONS

BY
CHARLES D. WALCOTT

(PUBLICATION 2444)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MAY 9, 1917

aff

The Lord Baltimore Dress

BALTIMORE, MD., U. S. A.

CAMBRIAN GEOLOGY AND PALEONTOLOGY

No. 1—NOMENCLATURE OF SOME CAMBRIAN
CORDILLERAN FORMATIONS

By CHARLES: D. WALCOTT

CONTENTS ne
EAE E OCT TO MMMM Rote c > sess aratios cat an cro ee RE Meee TS aya Slave ayes GelSlalen ave ale algveis I
Sem EL EcUtaecttln ROLMALION 4:2 5 acie.clePtieesare vere Oise cet isis. bisvalsteleis ol cvaiece siadavets g I
Sechionsat ctarmican Pass ands Reales. oo cieccis ccc sews meres ceen 2
The Ross Lake shale member of the Ptarmigan formation (Albertella
AEC MMe Poe Tere ras ais. s es oh 0, Rina A Eee Pa em orate a Rie cia sis Sonn Seaa ee 4
ch tatamVNOSIN TEIN OLMTAGLOM acs «ys a)s, cc esis cree rete eo wel e viel ce ol ayeaye Wels) one 4
eer iad ert SECON 5 (ora: ¢ sce eRe wees 6 ol ob oe ove sige ash whe 5
ateviewar Vo thitaltt SECCION. .. <mc nee sic sianars crave sis sia cela ciele wes’ a 5
Gre MELO HITE OMEN cree cas: sso hae ie ARERR eee re tterete cle clever Sine cies oe Acts 6
DinGenperesonmation.. Walcott. & Y.eeeee eens s Galoc ceo e selec bs ciee nes elele 7
USGI SUNK SOR a eS RAE bo, So ert ee ne eT One ar eee ae 7
Changi) ian’ Slaclley ARSe es eee eee een» 2 UR ty oe a 8
INTRODUCTION

This is the second title on this subject, the first having appeared
in 1908.’ Since that date a few new names for formations of Cam-
brian age in the Cordilleran area have been proposed, and I now have
two new ones and a definition of one used by me in 1912.”

THE PTARMIGAN FORMATION

The name Ptarmigan formation is proposed for a series of lime-
stones and interbedded shales that occur above the Mount Whyte
formation.of the Lower Cambrian and beneath the Cathedral forma-
tion of the Middle Cambrian in Alberta and British Columbia,
Canada.

Type locality—Southeast slope of Ptarmigan Peak above Ptar-
migan Lake 4.75 miles (7.6 km.) northeast of Lake Louise Station
on the Canadian Pacific Railroad, Alberta.

* Smithsonian: Misc. Coll., Vol. 53, 1908; No. 1, pp. I-12.
* Fort Mountain. Monogr. U. S. Geol. Surv., No. 51, p. 131, footnote a.

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 1

2 SMITHSONIAN MISCELLANEOUS COLLECTION VOL, 67

Derivation—From Ptarmigan Peak and Lake, the type locality.

Character.—Arenaceous gray limestones with interbedded bands
of thinner bedded, dark bluish-black limestones and some interbedded
bands of shale.

Thickness —At Ptarmigan Peak 516 feet (157.3 m.). At Ross
Lake, 8.5 miles (13.6 km.) west-southwest of Ptarmigan Lake, 664
feet (202.4 m.).

Organic remains.—Middle Cambrian fauna (lower) including the
Albertella fauna of Alberta and British Columbia.

SECTION AT PTARMIGAN Pass AND PEAK

The typical section was measured on the east and northeast face of
Ptarmigan Peak above the Pass and Lake. It is 5.5 miles (8.8 km.)
northeast of Lake Louise Station on the Canadian Pacific Railroad,
Alberta, Canada. The summit of Ptarmigan Peak is formed from
the Cathedral limestone, and a fine section is exposed from the summit
down to the lake and on the northeast slope down to the pre-
Cambrian.”

CATHEDRAL FORMATION : MIDDLE CAMBRIAN Teer

1. Massive-bedded, arenaceous, cliff-forming limestone, mostly of a
light gray color but with a few dark, lead-colored bands of more or less
irregular boundaries above and below. The dark bands are usually
formed of more thinly bedded and a finer arenaceous limestone........ 2,100
No fossils except traces of annelid borings.
The thickness of 2,100 feet is an estimate based on the height of the
mountain and the height of the base of the light gray arenaceous lime-
stone above Ptarmigan Lake.

PTARMIGAN FORMATION

1a. Thin-bedded, fine-grained, hard, dark gray to grayish-black arena-
CEOUS TIMESEONE 2.2 hac casos oa Ne Rirals ceo pe eee ceTe ee eee 46

Fauna: (63b) Zacanthoides cimon Walcott

Neolenus constans Walcott

This bed usually breaks down to form a slope beneath the massive
Cathedral limestone, but in places it forms a steep, low escarpment.

1b. Finely arenaceous limestone in thick alternating bands of a light
gray and dark lead gray color. The lower 20 feet is a light gray, finely
arenaceous laminated limestone, the lamella showing finely on the
jveathered 4surface Vos s)h osc Ce slek ree oa hana Deoehslos neo es eae bones 270

Fauna: Traces of annelid borings occur abundantly within the layers
and on their surface. The Ross Lake shale member of the Ptarmigan
formation, if present, should occur about 100 feet down in this section.

Smithsonian Misc. Coll., Vol. 53, 1910, p. 420.

NO. I CAMBRIAN CORDILLERAN FORMATIONS 3

1c. Massive-bedded, bluish-gray and light gray more or less finely
arenaceous limestone with many dark layers of oolitic limestone, the
oolites varying from 5 to 25 mm. in diameter.............cceeeceseeee 110

Fauna: A few minute fragments of trilobite tests were seen.

1d. Thin-bedded, dark, bluish-gray limestone that may or may not

Retarnea ORtIOMe OLotMerClILL sts nttetnetetere atts ater otis ccs tehes cheatin AL melee « 28
Fauna: (63d) Lingulella sp. undt.
Wimanella?

Ptychoparia (granulated species)
Ptychoparia ? cilles Walcott
Crepicephalus chares Walcott
1e. Finely laminated and shaly bluish-gray limestone with a few inter-
eee EE U eet) 1OUVELS)..f5). > skrha terete sei ateeE Gurl Ob Beale aiele # no's Laine oes <ua'y 62
This band of almost fissile limestone and shale is a marked feature
in the section. It is crossed diagonally by joint planes that cause it to
weather into projecting points that give the effect of the irregular sur-
face of dogtooth spar. This may be seen on the face of the cliffs of
Ptarmigan Mountain for a long distance, also on Fort Mountain on the
southeast side of the Pass.

Poa tmekness of Ptarmigan fOrmarion. c.¢..-4.0. eos ee coe ete re oe 516

Observations —The Ptarmigan formation is indicated in the Ross
Lake section by 664 feet (202.4 m.) of hard, thin layers of more or
less arenaceous limestones above the Mount Whyte formation and
beneath the massive Cathedral limestones. Owing to the rapid
change in character of many of the limestones within a short distance
in many instances it is difficult to trace the upper and lower bounda-
ries of a series of beds, like those of the Ptarmigan formation. Fre-
quently a modified alteration resulting from compression or mag-
nesian infiltration will completely change the appearance of the beds,
and often what appears to be a solid, massive-bedded limestone,
when seen in a cliff, may be a thin-bedded fossiliferous limestone
where broken down by erosion. On Mount Stephen I measured the
horizon of the Ptarmigan formation in the great eastern cliffs of
the mountain and there all the beds appeared to form one great
series of massive layers 1,560 feet (475.6 m.) in thickness.» To
determine the distribution and thickness of the Ptarmigan formation
in the Cordilleran area will require the extensive and thorough
examination of most if not all of the accessible sections of the Middle
Cambrian strata of the Canadian Rocky Mountains. It is possible
that the formation is only a broad local lentile that was deposited in
a depression of the Lower Cambrian sea bed. My first field impres-
sion was that the Ptarmigan limestone was deposited locally in a

* Canadian Alpine Club Journal, Vol. I, 1908, p. 2309.

4 SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67

shallow basin largely as oolites before the coming of the physical
change that produced the great Cathedral limestones.

It may be that it is an error to include the Ross Lake shale with its
Albertella fauna in the Ptarmigan formation. That is one of the
problems for the future worker in this field to determine.

THE ROSS LAKE SHALE MEMBER OF THE PTARMIGAN
FORMATION (ALBERTELLA ZONE)

A name proposed for the fine siliceous shale carrying the Albertella
fauna in the Ptarmigan ? formation.

Type locality.—In cliffs above Ross Lake, 1 mile (1.6 km.) south-
southwest of Stephen Station on the Continental Divide and south of
the Canadian Pacific Railroad. .

Deriwation——From Ross Lake where the shale is finely exposed
in the cliffs above the Lake.

Character.—Dark gray, fine siliceous shale with local fillets and
thin layers of gray limestone.

Thickness.—From 7 to 11 feet (2 to 3.3 m.).

Organic remains.—The known fauna includes the following:

Sponge spicules

Eocystites ? sp. undt.
Micromuitra (Paterina) wapta Walcott
Obolus parvus Walcott

Acrothele collenit Walcott
Wimanella simplex Walcott
Hyolithellus flagellum (Matthew)
Hyolithellus hectori Walcott
Hyolithes cecrops Walcott
Agraulos stator Walcott
Olenopsis cf. americanus Walcott
Albertella boswortht Walcott
Albertella helena Walcott
Vanuxemella nortia Walcott
Bathyuriscus rossensis Walcott

FORT MOUNTAIN FORMATION

In 1908 the quartzitic sandstones of this formation were described
as the “ Fairview formation.”* As that name, however, was pre-
occupied in American geologic nomenclature, and as the lower part
of the formation was subsequently found exposed at several places
on the east side of the Bow River Valley, it was decided to apply the
name Fort Mountain sandstone to the whole, from the typical

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 5.

NO. I CAMBRIAN CORDILLERAN FORMATIONS

exposures on Fort Mountain,’ which is situated on the northeastern
side of Bow Valley about 5 miles (8 km.) northeast of Lake Louise
Station on the Canadian Pacific Railroad, Alberta, Canada. Here
the basal conglomerate is seen in contact with the pre-Cambrian and
above it there is a band of shale 44 feet (13.4 m.) thick. This basal
conglomerate has a thickness of 360 feet (109.7 m.) and is much
coarser than on Saddle Mountain or Mount Temple.

PTARMIGAN PEAK SECTION

Two miles (3.2 km.) to the north, on the northeast side of Ptar-
migan Peak, the Fort Mountain formation is much thinner. A
measured section gave:

Feet
1. Thick-bedded, light gray, occasionally cross-bedded, quartzitic
sandstone with a little trace of purple color in a few layers............ 260
2. Light gray to brownish gray sandstone in thin layers.............. 22
3. Massive-bedded conglomerate, with white quartz pebbles and frag-
ments of dark and greenish fine, arenaceous shale in a coarse sandstone
HMGINAES 6.5 SWE BOO oe aotes BOIERGS ore On do Oot ea Dat or ees eras meet 170
“SEE ia 24,2 oS Oe IE ISIE Dee ares 2S Ar ics) i 452

[ UNCoNFoRMITY |

PRE-CAMBRIAN ARENACEOUS SHALES

The impression given by the above section is that the sediments
_ were deposited on the slopes of a pre-Cambrian shore line and did
not accumulate to the thickness of the deposits seen 3 miles (4.8 km.)
to the south-southwest at Fort Mountain.

FarrvIEW MounrtTAIN SECTION

On the north face of Fairview Mountain above Lake Louise, 6
miles (9.6 km.) southwest of Fort Mountain, the Lake Louise shale
forms a slight break in the cliffs that affords a foothold for small
coniferous trees and there is usually a quantity of green mosses or
lichens. Below the green vegetation the Fort Mountain formation
forms a wall of hard quartzitic sandstones. This same feature is
also present on the north face of the adjoining Saddle Mountain and
eastward on the cliffs of Mount Temple and in the Valley of the Ten
Peaks, above Moraine Lake. At Fairview Mountain the section
below the Lake Louise shale is as follows:

*See Monogr. U. S. Geol. Surv., No. 51, 1912, p. 131 footnote a.

6 SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67

Fort MountTAIn ForMATION Feet

1. Massive-bedded, purplish, hard cliff-forming fine-grained, quartzitic
sandstone in layers 6 inches to 3 feet thick, forming a vertical cliff in its
upper 150 feet (45.7 m.). Color gray in upper layers and gradually
becoming purplish colored with gray bands. Some layers are slightly
CFoss-Beddedice. Scie sietelas te wie «a ‘sfc State net ME naR Ie ane ereT eT rare ee eee a 350

On Mount Temple this sandstone has a strong purple color and in the
lower portion bands of arenaceous purple shale.

2. Hard gray, rather coarse-grained sandstone in the upper 200 feet
(60.9 m.) with bands of shaly beds from a few inches to a foot or more
in thickness. Below the sandstone becomes coarser and passes into a
fine quartz conglomerate forming massive layers..............00.ee00- 570

3- wiliceous: gray and greenish gray shale. <2. 4..5 «osccoe eee 20-++

Slope covered with débris.

On the north slope of Saddle Mountain a mile (1.6 km.) southeast this shale
has a thickness of 28 feet (8.5 m.) and below it about 100 feet (30.4 m.) in
thickness of coarse gray sandstone to fine conglomerate is exposed. On the
north slope of Mount Temple 2.5 miles (4 km.) northeast of Saddle Mountain
the basal beds of the lower portion of the sandstone and fine conglomerate
beds of the Fort Mountain formation rest on the dark, pre-Cambrian arena-
ceous shales. The section above is not accessible for measurement.

Ten miles (16 km.) further southeast on Little Vermilion Creek the basal
conglomerate is in massive layers, but the contact with the pre-Cambrian is
obscured by débris.

Summary.—The Fort Mountain formation consists of four members in its
greatest development:

; Feet

a.. Ouastzitie “sandstone yw snes thee a hee nee eee 350
b;, Coarse Waand stone. s5 2:25) tela tesco eae eee eter ee eae 570
ey Siliceoustsiale yc sist . 4 oS heels Greiner as aie eee 44
d. Arenaceous, quartzitic conglomerate ..............:...-- 360
Alec) bgt cs EPO eo CRT EP clininltnes beMRINr rate DE aan 1,324

It is delimited above by the Lake Louise shale and below by the basal con-
glomerate resting on various beds of the arenaceous pre-Cambrian shales.

ELDORADO FORMATION

Type locality.—Prospect Peak, Eureka District, Nevada.

Derivation —From Eldorado Mine on east slope of Prospect Peak.

Character.—Gray compact limestone in massive layers.

Thickness.—3,050 feet (929.8 m.) in the Eureka District, Nevada.

Organic remains.—Middle Cambrian fauna.

This formation is described in detail by Arnold Hague as the
Prospect Mountain limestone,’ but as the term Prospect Mountain
quartzite preceded it the term Eldorado was proposed by Walcott,’
and the term Prospect Mountain restricted to include only the quart-
zitic sandstone beneath.”

*Third Ann. Rept., U.S. Geol. Surv., 1883, p. 254. °
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 184 (footnote). °Idem, p. 12.

NOI CAMBRIAN CORDILLERAN FORMATIONS

DUNDERBERG FORMATION, WALCOTT *

Type locality Hamburg Ridge, Eureka Mining District, Nevada.

Its distribution is shown on the geological map of the Eureka
District accompanying the Third Annual Report of the United States
Geological Survey (1883, pl. XXIV).

Derivation —Dunderberg Mine, on Hamburg Ridge.

Character.—Arenaceous and calcareous shale with cherty nodules.

Thickness.—350 feet (106.7 m.) on Hamburg Ridge.

Organic remains——Upper Cambrian.

This formation is described by Arnold Hague as the Hamburg
shale, but as the Hamburg limestone preceded it the term Dunder-
berg was proposed by Walcott.’

GORDON SHALE

A name proposed for the fine. argillaceous shales carrying the
Albertella fauna in Montana.

Type locality—On Gordon Creek 6 miles (9.6 km.) from South
Fork of Flathead River, Ovando quadrangle (U. S. G. S.), Powell
County, Montana. The shale extends across the ridge between
Gordon and Youngs Creeks, about half-way between Gordon Mount-
ain and Cardinal Peak.

Derivation—From Gordon Creek and Mountain.

Character.—Greenish and purplish fine argillaceous shale.

Thickness.—284 feet (86.3 m.) on ridge between Gordon and
Youngs Creeks.

Organic remains.—The known fauna includes the following:

Alge (4v)

Hyolithes cecrops Walcott (4v)

Micromitra (Iphidella) nyssa Walcott (4q)
Micromitra (Iphidella) pannula (White) (4v, 4q)
Obolus (Westonia) ella (Hall and Whitfield) (4v)
Lingulella sp. undt. (4v)

Acrothele colleni Walcott (4v, 4q)

Acrothele panderi Walcott (4v, 5) )

Wimanella simplex Walcott (4v, 4q, 4w)
Ptychoparia candace Walcott (4v, 4q)

Ptychoparia charax Walcott (4v, 4q)

Ptychoparia pylas Walcott (4q)

Zacanthoides cnopus Walcott (4v, 4q, 4w)
Olenopsis ? americanus Walcott (4v)

Albertella helena Walcott (4v, 5j)

Vanuxemella contracta Walcott (4v, 5j)
Bathyuriscus belesis Walcott (4v, 4q)
Bathyuriscus belus Walcott (4w)

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 184 (footnote).

SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67

Locality 4q=about 315 feet (96 m.) above the unconformable
base of the Cambrian and 190 feet (57.9 m.) above the top of the
quartzitic sandstones, on the ridge between Gordon and Youngs
Creeks, about half-way between Gordon Mountain and Cardinal
Peak.

Locality 4v=about 200 feet (61 m.) above the unconformable
base of the Cambrian and 75 feet (22.9 m.) above the top of the
quartzitic sandstones, Gordon Creek, 6 miles (9.6 km.) from South
Fork of Flathead River.

Locality 4w=same horizon as 4q above, on Youngs Creek, about
5 miles (8 km.) from its junction with Danaher Creek.

Locality 5j=above the quartzitic sandstones, about 6 miles
(9.6 km.) west-northwest of Scapegoat Mountain, on the Conti-
nental Divide between Bar Creek and the headwaters of the south
fork of North Fork of Sun River, Coopers Lake quadrangle
CUS Gas):

The first three localities are in Ovando quadrangle (U. S. G. S.);
all four in Powell County, Montana.

CHISHOLM SHALE
See Smithsonian Miscellaneous Collections, Vol. 64, 1916, p. 409.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOLUME 67, NUMBER 2

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

IV
No; 2;—1HE ALBERTELEA FAUNA IN BRITISH
COLUMBIA AND MONTANA

(WirtH PtatTEs 1 TO 7)

BY
CHARLES D. WALCOTT

(PUBLICATION 2445)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MAY 9, 1917

The Lord Galtimore Press

BALTIMORE, MD., U. 8. 4.

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CAMBRIAN GEOLOGY AND PALEONTOLOGY

No. 2—THE ALBERTELLA FAUNA IN BRITISH
COLUMBIA AND MONTANA

By CHARLES D. WALCOTT

(WitH PLATES I TO 7)

CONTENTS PAGE
UTES SD a salt ae eR RS Re 9
ldentiication of tle eenus Albertella. 1.25.65. c eerie cee s see cee 10
ear Mata CM EISIEIOLT Pac. 3).' a's ape eee mae eee Lite ok Abe ailaeeveg od ds ined dae IT
IRGRS, ILA RE Qe ee tO ns Cina cet hs Ore eee oa ee are eee 13
eR See RT = 5.62.2 PPI ns Ae ot ns Daa ho Sitio a nies Gee Ses 14
emer TT aSECIION. < ©5 oe eiiee pees aes tee cee s ek we eels eS ae ees ses 15,
Faunal characteristics .......... - its 22s SE ENGI AIR aD a aL PTE IO
MEI AECONISHCONSH DI ACEIt Talia, eee cee Meets ce cae bec. bine ve oles sees wiele Ig
eS IMeMEO) SHPCLI ACE AUMA sh. oak eels Wow tie sn Dietde a Maclile tle die onic eee ees 20
OU S80 Scr ie EVE 2 Se Se oe ie 22
WescriptionPoimeenecan anid :SPeClESs cir a ciac Haat ders vce ve edie sd dials ele toe sie 24
ILLUSTRATIONS
PLATES FACING PAGE
Pee anieaume view Gb MLOUNt- DOSWOLED, oc .c.. cas each ks oie eds cow eae eee es 12
Be VoOssmeakcerctrgterand POpes mealens seeisicss one geist «vine coeelde grees bau I4
3. Profile view of north cliff of Ross Lake Mountain..................00: 5.
4-7. Illustrations of fauna of Ross Lake and Gordon shales and of the
limestones of the Ptarmigan and Chetang formations........... 52-58
INTRODUCTION Hived wn

When discussing the Dearborn River section in 1908* I stated:
that the Albertella fauna of the Montana sections was placed in the
Lower Cambrian as the fauna was strikingly similar to that occurring
in the drift blocks which were believed to have come from the lower
portion of the Mount Whyte formation of the Mount Bosworth
section of British Columbia; that the Mount Whyte formation was

* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 202, 203.

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No.

Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

placed in the Lower Cambrian owing to the presence of trilobites of
the genus Olenellus; that the presence of Albertella in the Mount
Whyte formation was based on the occurrence of numerous trilobitic
cranidia that appeared to be generically identical with the cranidia
of Albertella.

The genus Albertella was subsequently identified in the Robson
Peak District in a drift block supposed to have been derived from the -
Middle Cambrian Chetang formation limestone about 350 feet above
the Hota formation which was referred to the Lower Cambrian.’

In 1914 Mr. L. D. Burling concluded after a thorough and admir-
able study that on paleontological evidence the Albertella fauna was
of Middle Cambrian age and that the specimens of Olenellus found in
the Mount Whyte formation were examples of recurrence. On
the basis of this conclusion Burling placed the Mount Whyte forma-
tion in the Middle Cambrian.

A notice of the discovery of the genus Albertella near the line of
the North Kootenay Pass by Dr. Frank D. Adams and Mr. W. J.
Dick,’ when looking for deposits of phosphate of lime, escaped my
attention until Dr. Adams mentioned it tome. There is nothing in the
section, however, to indicate the stratigraphic position of the fossils
in relation to a known Lower Cambrian fauna.

Recently (January, 1917) through the courtesy of Dr. Adams I
have had the opportunity of looking over the fossils. They are not
well preserved on the surface of the shaly limestone, but it is possible
to tentatively determine the following genera and species:

Agraulos stator Walcott

Vanusxemella nortia Walcott
Albertella bosworthi Walcott
Asaphiscus rossensis Walcott

In 1916 Burling described a locality of the Albertella fauna in situ
on Mount Bosworth and stated that the fauna was of Middle Cam-
brian age.”

IDENTIFICATION OF THE GENUS ALBERTELLA

At the time of the preliminary identifications of the faunas, in
connection with the publication of “ Cambrian Sections of the Cordil-

1 Smithsonian Misc. Coll., Vol. 57, 1913, p. 338.
? Canadian Geol. Surv., Museum Bull., No. 2, Geol. Ser., No. 17, 1914, p. 36.
® Commission of Conservation, Canada, Discovery of Phosphate of Lime in
the Rocky Mountains. 8vo pamphlet. Ottawa, 1915, p. 13. ‘
*Summed up in article in American Journal Science, Dec., 1916, 4th Ser.,
Vol. 42, pp. 460-472.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA II
leran Area,” in 1908,’ I did not fully appreciate that trilobites with
almost identical cranidia might have a dissimilar thorax and
pygidium and belong to quite distinct genera. This conclusion came
later, when studying groups of Cambrian trilobites retaining their
entire dorsal shield so that the cephalon, thorax, and pygidium of
many genera might be compared.”

During the winter of 1915-16 I studied all the material available of
the genus Bathyuriscus, and found that my previous conception of
that genus was inaccurate,’ and that species from the Mount Whyte
formation I had referred to a new genus, Bornemannia,’ were to be
included under a subgenus of Bathyuriscus. Another result was to
question the identification and presence of the genus Albertella in the
Mount Whyte formation as it was based only on specimens of the
cranidium. This was not carried further before I left for the field
in June, 1916, but was taken up on my return in October. This review
has now led'to the elimination of the genus Albertella from the lists of
the fauna of the Mount Whyte formation and this includes the lists
from localities 35e and 57e as published in the description of Bathyu-
riscus (Poliella) primus.

The available field notes and fossils of the Mount Whyte formation
are now being studied, but it may be necessary for me to visit some
of the typical localities before expressing an opinion as to the desira-
bility of including a portion of the Mount Whyte formation in the
Middle Cambrian as so strongly urged by Burling.’

STRATIGRAPHIC POSITION

The exact stratigraphic position of the typical Albertella fauna
was unknown to me when I went to the field in June, 1916, although
Burling had stated in a general way that he had found it on Mount
Bosworth in the Cathedral formation and I had a specimen from the
Cathedral limestone of Castle Mountain. The fauna was originally
referred to the Lower Cambrian,’ but neither in British Columbia
nor Montana was there at that time a known occurrence of the fauna

* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 167-220.

* See Asaphiscus. Smithsonian Misc. Coll., Vol. 64, 1916, pp. 382, 383.

* Smithsonian Misc. Coll., Vol. 64, 1916, p. 332.

*Tdem, p. 352.

*Idem, p. 353. “

*Geol. Surv. Canada, Museum Bull. No. 2, Geol. Ser., No. 17, 1914,
pp. II2-115.

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 202.

12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 607

as a whole in situ in a section that proved to me beyond question its
stratigraphic relation.

The position of the fauna found in drift blocks in British Columbia
was assumed from the identification of cranidia in the Mount Whyte
formation, and this was also extended to a similar fauna found in
broken and isolated sections in Montana. During several field
seasons in Alberta and British Columbia a general outlook was kept
for traces of the Albertella fauna, but at no time was it convenient
for me to go back to Mount Bosworth to systematically search for it,
but in July, 1916, I began a search for the fauna in the Mount Whyte
formation and the superjacent Cathedral limestones. The latter were
included as in 1907 the cranidium and pygidium of a species of
Albertella were found in the limestones of the Cathedral formation
275 feet (84.6 m.) above the top of the Lower Cambrian on the east
shoulder of Castle Mountain, Alberta, which is 19.5 miles (31.2 km.)
east-southeast of the Ross Lake section of 1915 and I had also noted
the presence of the cranidium and pygidium of Albertella bosworth
in débris of the Chetang formation which was referred to the Middle
Cambrian.’

We knew from the collection of 1907 at Castle Mountain and from
Burling’s find on Mount Bosworth that the genus was present in the
Middle Cambrian Cathedral limestone, but I did not know that the
genus Albertella was not present in the Mount Whyte formation.
I have not discussed the finds in the Middle Cambrian heretofore as
I was waiting for the time when the Albertella fauna of Mount
Bosworth should be accurately located in the section.

The first section examined was that of the eastern ridge of Mount
Assiniboine 18 miles (28.8 km.) southwest of Banff, Alberta, but
without finding any trace of the fauna. Section after section was
then studied on the main range to the north and northwest, but it
was not until August 24 that the Albertella fauna was located im situ
in a hanging glacier cirque above Ross Lake and 1 mile (1.6 km.)
south-southwest of Stephen on the Canadian Pacific Railway. After
locating the stratigraphic horizon of the siliceous shale and included
Albertella fauna I crossed to the north side of the broad Kicking
Horse Pass and found it after a day’s search in situ on the southern
slope of Mount Bosworth west of Burling’s locality. The band of
shale is from 7 to 11 feet (2 to 3.3 m.) in thickness, and the little
terrace formed by it is almost always covered by dirt, broken rock,

* Smithsonian Misc. Coll., Voi. 57, 1913, p. 338.

SMITHSONIAN Je VOL. 67, NO. 2, PL. 1

Cathedral

Panoramicte best exposed Cambrian sections in the Rocky Mountains.’
Including # ™.) in thickness of strata are exposed. The approximate posi-
tion of the iqot Burling is on the right toward or near A. (Photograph by

Walcott, 1916.)

_—T— «©.

~~ =

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 67, NO. 2, PL. 1

“)

ia,»

Sherbrook

Cathedral
oo

“A. Ptarmigan

si: \— Mt.Whyte
t.Piran

Panoramic view of Mount Bosworth, on the Continental Divide, from Ross Lake cirque, looking north across the Kicking Horse Pass.

_ Including the Lower Cambrian sandstones on the right (east) and the Upper Cambrian Sherbrook limestones on the left (west) over 12,000 feet (3,657.4 m.) in thickness of strata are exposed.
tion of the formation is indicated and the Albertella zone by A. A.
Walcott, 1916.)

1 Smithsonian Misc. Coll., Vol. 53, 1908, pp. 204-217.

This is one of the best exposed Cambrian sections in the Rocky Mountains.’

The approximate posi-
We found the latter fauna in situ on the left at 4, and I suppose that the locality of Burling is on the right toward or near A Photograph by
p y g

NO. 2 . ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 13

trees, and brush. This so effectually conceals the band of shale
that unless one knows just where to look there is little chance of
finding it except in some such favorable locality as that above Ross
Lake or the two known places on Mount Bosworth. The Albertella
fauna is probably present all the way from Mount Assiniboine to
Ross Lake, but conditions were not favorable for its discovery either
in shale or limestone.

Stratigraphically the fauna as now known has a limited vertical
range and a rather wide geographic distribution. The Ross Lake
shale has a thickness of 7 feet (2 m.) in the Ross Lake section and
about 10 feet (3 m.) on Mount Bosworth. Albertella also occurs in
the adjoining limestone, but its vertical range there is unknown. :

The genus is known from the Robson Peak District about 200 miles
(320 km.) north-northwest of Mount Bosworth, also about 285 miles
(456 km.) to the south in the vicinity of Gordon Mountain in the state
of Montana."

Albertella helena occurs in Montana and at Mount Bosworth, and
Albertella bosworthi in the Robson Peak District.

Ross LAKE SECTION

Ross Lake is situated on the south side of the Canadian Pacific
Railway 1 mile (1.6 km.) south-southwest of Stephen Station on the
Continental Divide. The section was measured on the northeast and
northwest sides of the amphitheater above Ross Lake on the north
-end of the northern spurs qf Popes Peak. The base of the Mount
Whyte formation rests on the purplish-colored massive quartzites
of the St. Piran formation on the west slope of the east spur and about
500 feet (152 m.) above Ross Lake ; the summit of the section as given
here is on the east face of the west spur.

MrippLtE CAMBRIAN
CATHEDRAL FoRMATION

Cliffs of massive-bedded rough arenaceous limestone rise one
above the other to the summit of the ridge. At Mount Bosworth on
the north side of the Kicking Horse Pass the Cathedral limestones
have a thickness of 1,086 feet (334 m.) exclusive of a lower division
of 509 feet? (156.6 m.), which I have now included in a recently
recognized formation named Ptarmigan from its typical section on
Ptarmigan Mountain above Ptarmigan Pass, 8 miles (12.8 km.) east-
northeast of Ross Lake.

* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 18-22.
* This is 1c-f of the Cathedral formation section of 1908 (Smithsonian Misc.
Coll., Vol. 53, 1908, p. 212).

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

PTARMIGAN FORMATION
1. Thin-bedded, more or less arenaceous and mottled limestone...
1a. Bluish-gray limestone in thin irregular layers interbedded in
a steenish siliceous shale... Jo)... 02% 2. we ee amas one ns oe ene
2. Greenish and dark gray, compact siliceous shale weathering to a
light gray color when long exposed. The shale forms compact,
solid, hard layers from 2 to 3 feet (0.6 to 0.9 m.) thick that break
first into blocks on joint planes and then split up into shale on long
exposure to frost and watef.. s,s. 25 ec eso cele vere « eet
This is the Ross Lake shale member of the Ptarmigan formation
which is characterized by the Albertella fauna which is most abun-
dant in many places in it. At the Ross Lake section the fauna
includes (Loc. 63j): .
Siliceous sponge spicules
Eocystites ? sp. ?
Micromitra (Paterina) wapta Walcott
Obolus parvus Walcott
Acrothele colleni Walcott
Wimanella simplex Walcott
Hyolithellus flagellum (Matthew)
Hyolithes cecrops Walcott
Agraulos stator Walcott
Olenopsis cf. americanus Walcott
Vanuxemella nortia Walcott
Albertella bosworthi Walcott
Albertella helena Walcott
Bathyuriscus rossensis Walcott
On the slope of Mount Bosworth the shale is a little thicker and
we collected from it in situ (Loc. 63m.) :
Acrothele colient Walcott
Wimanella simplex Walcott
Hyolithes cecrops Walcott
Agraulos stator Walcott
Vanuxemella nortia Walcott
Ptychoparia sp. undt.
Olenopsis cf. americanus Walcott
Albertella boswortht Walcott
Albertella helena Walcott
Bathyuriscus rossensis Walcott
From the boulders (Loc. 35c) found below the outcrop on the
south slope of Mount Bosworth in earlier years there have been
collected:
Micromitra (Paterina) wapta Walcott
Obolus parvus Walcott
Acrothele collent Walcott
Wimanella simplex Walcott
Hyolithellus fagellum (Matthew)
Hyolithellus hectori Walcott

Feet
155

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SMITHSCNIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 2, PL. 3

CATHEDRAL

PTARM/GAN

MT. WHYTE

ST PIRAN,

North profile of ridge above and southeast of Ross Lake, 1 mile (1.6 km.)
south of Stephen Station on the Canadian Pacific Railway.

The position of the Albertella zone is shown at A where the thin band
of shale forms a dark, narrow band that may be seen from the Kicking
Horse Pass.

The relative positions of the Cathedral, Ptarmigan, Mount Whyte, and
St. Piran formations are indicated on the plate.

This view should be studied in connection with plate 2. (Photograph by
Walcott, 1916.)

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 15

Hyolithes cecrops Walcott
Agraulos stator Walcott
Ptychoparia sp. undt.
Olenopsis cf. americanus Walcott
Vanuxemella nortia Walcott
Albertella bosworthi Walcott
Albertella helena Walcott
Bathyuriscus rossensis Walcott Feet
3. Massive-bedded, gray and mottled, rough weathering arena-
Ee TIS MIILES [OME et. tel Sorel ie anes estan saree ore oes ous Lo Siaca-o Bao wie evar 160

5. Massive-bedded, dirty gray colored, rough weathering calca-
GEOUSMSAGSHOM Chea soi. cand eR ae scihevele alas wale 6 eve ee wed 275
6. Alternating layers of bluish-black and steel-gray hard limestone 52

Hotalareterted to etapimicam mOGMAtMOM. 4.06 0..te 00+ 100 de oe - 664
Lower CAMERIAN
Mount WHuyte ForMaAtion
1. Gray to grayish-black thin-bedded oolitic limestone............ 43
Fossils: Many small fragments of trilobites.

At this horizon 5.5 miles (8.8 km.) to the south at the west foot of
Mount Shaffer, British Columbia (Loc. 61d), the following fauna
has been collected :

Acrotreta sagittalis taconica Walcott
Nisusia (Jamesella) lowi Walcott
Scenella varians Walcott

Pelagiclla sp. undt.

Micronutra (Paterina) labradorica (Billings)
Micromitra (Iphidella) pannula (White)
Corynexochus senectus (Billings)
Agraulos unca Walcott

Zacanthoides

“Ptychoparia (Emmrichella) lux Walcott
Ptychoparia sp.

Mesonacis gilberti (Meek)

2. Finely banded gray sandstone and hard arenaceous limestone... 5

3. Gray, finely oolitic limestone in thick beds that break down
CMT Ie OU at lay LSet ee vole ia oe ales Socisid swe velscessss 18

Fauna: At 15 feet from summit (Loc. 63k) :
Nisusia (Jamesella) lowi Walcott
Pelagiella sp. undt.

Helcionella elongata (Walcott)
Scenella varians Walcott
Hyolithes billingsi Walcott
Ptychoparia cercops Walcott
Ptychoparia pia Walcott
Olenopsis agnesensis Walcott

16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Feet
4. Banded sandstone and finely arenaceous shale in massive beds
that break down on weathering into shaly arenaceous layers usually
covered more or less thickly with annelid trails and more rarely

tracks of trilobites? 2... ccccscte i actecticreeia tien eh ee ae Chee ee 70
5. Greenish, drab and buff-colored very fine siliceous shale with
pattings of thin layers of Ccompact,sandstone.... .....- es -eeeeeee 85

Fossils: Noted a valve of Micromitra and cranidium of
Ptychoparia.
6. Calcareous sandstone with dirty brown and rusty layers and
shaly sandstone parting@s. «2... cc. s<cksfincs's ss soa oe eee 27
Fossils:
Corynexochus fieldensis Walcott
Olenellus (many fragments ) —
Total thickness of Mount Whyte formation................. 248
St. Prran ForMATION

Massive-bedded purplish quartzitic sandstones that form cliffs
above Ross Lake.

The above sections of the Mount Whyte and Ptarmigan forma-
tions show that the Albertella fauna is located in the Ross Lake
section some 500 feet (153.8 m.) above the top of the Mount Whyte
formation and the Olenellus fauna. In the section of Castle Moun-
tain 15 miles (24 km.) southeast of Ross Lake a specimen of the
pygidium of Albertella boswortht was found in 1907 260 feet
(79.2 km.) above the Mount Whyte formation in a thin-bedded
limestone that was then referred to the Cathedral formation, but
which is now included in the Ptarmigan formation.

MONTANA AREA

In Montana the Albertella zone is weil developed in Powell County
at localities about 285 miles (456 km.) south of Kicking Horse Pass,
British Columbia, and 135 miles (216 km.) south of Dr. Frank D.
Adams’ locality near North Kootenay Pass. The Cambrian section
in this area, as I measured it in 1905, resembles that of Dearborn
River and that of the Little Belt Mountains, but as the known fauna
is different in the lower shale containing Albertella, I have named
that shale the Gordon shale.

GORDON MOUNTAIN SECTION

The section is exposed along the ridge between Youngs Creek and
Gordon Creek. The base of the section begins on the saddle beneath
the limestone cliff half-way between Gordon Mountain summit and
Cardinal Peak, and extends east-northeast along the ridge above-
mentioned. Beginning with the top of the section we have the
following succession. The section above ta of the Yogo limestone
is cut off by a twist and a fault in the beds.

NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 17

Yoco LIMESTONE Feet

1a. Light gray limestone in layers 3 to 8 inches thick. It is oolitic
in some layers and has many annelid borings and trails.............. 430
ie Warkeray linestone similar to Ta: e222... .60. Fo. ec ae 190

Strike E. and W., dip 45° N. (Mag.).
1c. Thin-bedded, bluish-gray limestone with many annelid borings
Suivdl - UEC on Bech a eka o cuceenG tacts caches CUCUCIER i aie, A 215

protalvor voroulimestonen meri vaclesce eek cette acces beak 835
Dry CrEEK SHALE
2. Green, argillaceous shale with a few thin layers of limestone inter-
bedded. The thickest of these is a band 3 feet thick 20 feet from

PEERS et us 85. 27a. Xm warden a aT eda sie oe TS en sii ines erase leas es 64
Fauna
Micromitra
Hyolithes
Asaphiscus (like wheelert)
Ptychoparia

Pincrim LIMESTONE
3. Thin, irregular layers of bluish-gray limestone that form massive
layers when not broken dowin’ bysweathering. .. 60.20 je. loccee ese cee 545
‘Traces of fossils
Dip reaches 80° near the top.
PARK SHALE
4. Green and gray argillaceous and arenaceous shale............... 47
Fauna, locality 8):
Micronutra (Paterina) superba Walcott
Bathyuriscus sp. undt.
Ptychoparia sp.
Zacanthoides sp.
MEAGHER LIMESTONE
5. Thin-bedded, gray, arenaceous limestone becoming purer a little
SIONS HDS BSE TE Arete ee Pes tre cn he rr 145
At 45 feet above the base the beds become more massive but
break down into thin layers on weathering.
Fragments of fossils occur.
GorDON FoRMATION
6a. Chocolate or purple argillaceous and sandy shales.............. 64
Fauna: Fragments of a fauna appear here which is well
developed in 6b.
6b. Dark greenish argillaceous shales, weathering a lighter green... 35
Fauna, locality 4q:
Micromitra (Iphidella) nyssa Walcott
Micromitra (Iphidella) pannula (White)
Acrothele collenit Walcott
Wimanella simplex Walcott
Ptychoparia candace Walcott
Ptychoparia charax Walcott
Ptychoparia pylas Walcott
Bathyuriscus belesis ? Walcott (Pygidia)
Zacanthoides cnopus Walcott

18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Feet
6c. Layers of impure, gray weathering, buff-colored limestone with
bands of dark greenish shale between thee siete Magee e ieitks a ee ee eee 21
6d. Greenish and bluish-gray argillaceous shales mat irregularly
interbedded sandy shales and thin layers of compact gray sandstone... 164
At 82 feet (25 m.) from the base a thin layer of sandstone
contains fragments of Albertella and the shales above carry
quite a fauna.
Locality 4v at the foot of the ridge on Gordon Creek is con-
sidered to come in at about this horizon. It is 75 feet (22.9 m.)
to 90 feet (26.8 m.) above the sandstone of 7a. It includes—
Alge
Hyolithes cf. cecrops Walcott
Micromitra (Iphidella) pannula (White)
Obolus (Westonia) ella (Hall and Whitfield)
Lingulella sp. undt.
Acrothele colleni Walcott
Acrothele panderi Walcott
Wimanella simplex Walcott
Ptychoparia candace Walcott
Ptychoparia charax Walcott
Olenopsis americanus Walcott
Albertella helena Walcott
Bathyuriscus belesis Walcott
Vanuxemella contracta Walcott
Zacanthoides cnopus Walcott
Hyolithes and Ptychoparia occur below in several bands of
greenish argillaceous shale between more sandy layers. —
Rotaliot Gordons tonmationn. pee sso seat ee eee 284
FLATHEAD ? SANDSTONE
7a. Thin-bedded greenish and brown Shdetone with shaly sand-
stone partings. Annelid borings and trails, mud cracks and ripple
IMATICS OCCUN ere sabre oie o Sle AIH. ct cleo cele rae helehe ore cde ar oon oe ee 43
Strike E. and W. (magnetic), dip 48° N.
Fauna: See footnote.’
7b. Gray sandstone in thick beds, some of which are a fine quartz
conglomerate with pebbles up to one-fourth of an inch in diameter.... 82
In a thin arenaceous layer 20 feet (6 m.) above the contact
with the Algonkian strata numerous fragments of a species of
Albertella were found.
otal ofsblatheadmn sandstone yan sec eieei eet sane 125

* At locality 150d, on the Continental Divide, about 24 miles (48.6 km.) north-
west of Scapegoat Mountain and 12 miles (19.2 km.) northeast of Gordon
Mountain, the Albertella fauna occurs in a thin-bedded shaly, browish sand-
stone. The following species were found:

Crusiana sp. undt.

Agraulos cf. stator Walcott
Albertella cf. helena Walcott
Vanuxemella contracta Walcott

This locality is of importance as it extends the stratigraphic range of the
fauna to the sandstones beneath the horizon of the Gordon shale.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA I9Q

RESUME

Feet
TARVOR TH UITESUONE (Cle. SeiacirMOE ie tek algae he ita ie eces 835
Pray Cte Shales woe ate tiees ts cella ts ode Gated «cles 64
Serb oni lime stOmes cp Mette: hicsaisiss ols crokeriare ora vaa/dera 6 545
dig JPBVEE SSS REAR lg CO OFS ei oe aOR SISOS ORIG aes Ce eee 47
Eee Vieaciren tittnlesStOnlen spaaeeiae cae sien. o o's bitrnks. oo c/s cxerarerere or 145
Pe OL OISHAG at oe Sn nee es Lae Sud ea sccee es 284
pet biathede © -Satidstonesktanet a ites es, cer dae is hones sais 125

Tove TR Rees cers Ook coe Ga SOE ICE a OIE Mio esere 2,045

The Cambrian section rests on gray and red shales and hard
sandstones of the Camp Creek series (Walcott, 1906*) of the
Algonkian. This section is, as far as known, on the western
limit of the Cambrian strata in Montana. To the north the
same series extends north up the valley of the South Fork of
Flathead River.

FAUNAL CHARACTERISTICS

The fauna of the Ross Lake shale or Albertella zone is of interest
both from its biological and stratigraphic aspects. Biologically, it
represents a small subfauna of the Middle Cambrian that is rich in
brachiopods and trilobites. The shale in which it occurs indicates
very favorable conditions for the presence of a much more varied
invertebrate life but as yet the fauna is limited to 14 known genera
and 16 known species. .

RELATIONS TO SUBJACENT FAUNA

The fauna of the subjacent Mount Whyte formation has been
misunderstood very largely through tentatively including in it the
Albertella fauna of the superjacent Ptarmigan formation. With this
eliminated we find the fauna at the base of the Mount Whyte forma-
tion of a Lower Cambrian facies, and near the summit the Lower
Cambrian fauna still predominating but with some genera that are
much more developed in the Middle Cambrian fauna above, notably
Crepicephalus, which is represented in the upper beds of the Mount
Whyte formation.

I have already mentioned the difficulty met with in identifying the
genus Albertella from fragments of the cephalon. The cranidium of
Alberteila is similar in form to some species of Bathyuriscus, notably
that of B. (P.) primus, which occurs in the Mount Whyte formation.
This is best seen by comparing the cranidia of the two genera as

* Bull. Geol. Soc. America, Vol. 17, 1906, p. 3.

20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

illustrated for Albertella on plates 1 and 2, Vol. 53, Smithsonian
Miscellaneous Collections, 1908, and for Bathyuriscus primus on
plate 46, Idem, Vol. 64, 1916. Thinking that probably the specimens
of Albertella helena and A. bosworthi found in loose blocks came
from a siliceous shale of the Mount Whyte formation, I identified
separate cranidia from that shale as Albertella, but now that I know
that Albertella helena and A. bosworthi in the Canadian Rockies
section occur in a siliceous shale 500 feet (152.4 m.) or more above
the Mount Whyte formation and that no typical form of the pygidiwm
or thorax of Albertella is known to have been found in the siliceous
shales or limestones of the Mount Whyte formation I do not hesitate
to refer the cranidia from the Mount Whyte formation to Bathyu-
riscus (P.) primus. This removes Albertella from the Mount Whyte
formation and restricts it to the Ross Lake shale and the Albertella
zone, and the limestones of the Ptarmigan formation in which the
Ross Lake shale occurs.

The remaining species of the Albertella shale: fauna that were

identified as occurring in the Mount Whyte formation are:
Micromitra (Paterina) wapta Walcott
Obolus parvus Walcott
Acrothele collent Walcott

Another species that occurs higher up in the Middle Cambrian
section, but not in the Albertella zone, is Micromitra (Iphidella)
pannula (White).

A careful study of the specimens that were hastily identified when
writing out the geologic sections in 1908" results as follows in rela-
tion to the species assumed to be identical from the Albertella zone
and the Lake Agnes shales of the Mount Whyte formation.

Micronmitra (Paterina) wapta Walcott—Fragments of larger
specimens of Micromitra (P.) pannula White were identified as
Micromitra (Paterina) wapta by me in 1908 and credited to (locality
35e) the Mount Whyte formation, where they occur with Acrothele
n. sp. In the form of fragments and with the outer surface injured
or exfoliated it is exceedingly difficult to recognize characters that
with better material indicate specific differences.

Obolus parvus Walcott from (locality 35c) the Albertella zone is
a small species nearly circular in outline. The species identified with
it from (locality 58t) the Mount Whyte formation is represented
by the interior of a ventral valve that is distinctly elongate and with

* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 204-217.
* Idem, p. 214, 3 of section.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND-MONTANA 2I

a very definite and nearly straight cardinal slope from the beak
outward to the lateral margins of the valve, and it is not Obolus
parvus. ‘The specimens identified as Obolus parvus from (locality
35e) the Mount Whyte formation * were probably dorsal valves of
young shells of Acrothele n. sp., which is abundant but usually poorly
preserved.

Acrothele colleni was identified from Mount Stephen in tc of
section. The specimens differ from the types of A. colleni from the
Albertella zone in uniformly smaller size and the presence in the
dorsal valve of a very long and strong median ridge, in this respect
resembling Acrothele bellula of the Middle Cambrian of Alabama.

By oversight Mesonacis gilberti is given as occurring in the fauna
of the Lake Agnes locality (35e).* It occurs in the same stratigraphic
section but at a lower horizon. On the opposite side of the Victoria
Range at Mount Shaffer M. gilberti occurs above the horizon of the
Lake Agnes shale fauna (35e) at locality 61d associated with a
typical Lower Cambrian fauna (List, p. 15).

RELATION TO SUPERJACENT FAUNA

The Albertella fauna is a small subfauna that includes primitive
forms usually found in the Lower Cambrian fauna, such as Micro-
mitra (Paterina) wapta, Agraulos stator, along with typical Middle
Cambrian forms. The next well-known superjacent fauna is the
so-called Ogygopsis fauna of the Stephen formation and just above
this the Burgess shale fauna, both of which are well-known Middle
Cambrian subfaunas. Between the Albertella zone and the base of
the Stephen formation there is a series of almost unfossiliferous
limestones forming the upper 165 feet (50.3 m.) of the Ptarmigan
formation and also the entire Cathedral formation of about 1,000
feet (304.8 m.) in thickness. That the period between the Albertella
zone and the Ogygopsis zone was of considerable length is evidenced
by the change in the faunas and by the appearance of a greater
diversity of forms in the Ogygopsis zone. This latter statement is
qualified by the possibility of the Ogygopsis fauna being an immi-
grant fauna from outside of the area where it is now found.

One of the problems now is to find the subfauna or faunas that
existed in early and late Ptarmigan time and throughout the period

* Smithsonian Misc. Coll. Vol. 53, 1908, p. 214, 3 of section.
* Idem, listed on p. 213.

°U. S. Geol. Surv. Monogr., No. 51, 1912, pl. 58, figs. 5f, 5h:
“Idem, p. 130.

.
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of deposition of the Cathedral formation. That this can be success-
fully accomplished by a systematic search in the Robson Peak Dis-
trict and to the north of it is quite possible as there are a number of
interbedded bands of thin-bedded limestones in the Chetang forma-
tion and bands of shale in the Hitka formation which appears to be
below the horizon of the Ogygopsis shale zone of the Stephen
formation.
NOTES ON THE FAUNA

In order that the geologist and paleontologist may have before
them what is known of the Ross Lake shale fauna as a whole, also the
Albertella fauna of the Gordon shale and the limestone of the Ptar-
migan formation and the Chetang formation, I have brought together
on plates 4-7 illustrations of the species known to me as they have
been found in the vicinity of Kicking Horse Pass, British Columbia ;
in Montana, and the Robson Peak District, Alberta. The following
references are simply for the purpose of indicating where the old
species are described, also the plates on which illustrations may be
found in this paper. J

The species from the Gordon shale have (Gordon) after the
specific name; those from the Chetang limestone (Chetang) ; those
from the Ptarmigan limestone (Ptarmigan), and those from the
Ross Lake shale are without a designation.

Thohasterella ? hindei n. sp., pl. 4, figs. I, Ia

Eocystites ? sp. undt., pl. 4, fig. 2.

Micromitra (Paterina) wapta Walcott (Monogr. 51, U. S. Geol. Surv., 1912,
p. 357), pl. 4, fig. 3

Micromitra (Iphidella) nyssa Walcott (Gordon) (Idem, p. 360, pl. 3, fig. 9)

Micromitra (Iphidella) pannula (White) (Gordon) (Idem, p. 361, pl. 4,
fig. Ig) ;

Obolus parvus Walcott (Idem, p. 408), pl. 4, figs. 4, 4a

Obolus (Westonia) ella (Hall and Whitfield) (Gordon) (Idem, p. 455,
pl. 47, fig. 1b)

Lingulella sp. undt. (Gordon)

Acrothele colleni Walcott (Idem, p. 640), pl. 4, figs. 5, 5a-f

Acrothele panderi Walcott (Gordon) (Idem, p. 651, pl. 50, fig. 5)

Wimanella simplex Walcott (Idem, p. 748), pl. 4, figs. 6, 6a-c, 7, 7a-c, 8,
8a-c

Nisusia cf. alberta Walcott (Chetang:), pl. 4, fig. 9

Hyolithellus flagellum (Matthew) (Canadian Alpine Journ., Vol. 1, 1908,
pl. 1, figs. 8, 8a), pl. 5, figs. 2, 2a

Hyolithellus hectori n. sp., pl. 5, fig. 1

Hyolithes cecrops n. sp., pl. 5, figs. 3, 3a-c

Agraulos stator Walcott (Smithsonian Misc. Coll., Vol. 64, 1916, p. 173),
pl. 6, fig. 6

Agraulos sp. undt. (fragment of a cranidium)

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 23

Ptychoparia candace n. sp. (Gordon), pl. 6, figs. 3, 3a

Ptycheparia charax n. sp. (Gordon), pl. 6, fig. 1

Ptychoparia ? cilles n. sp. (Ptarmigan), pl. 6, fig. 2

Ptychoparia pylas n. sp. (Gordon), pl. 6, figs. 4, 4a-c

Ptychoparia sp. undt. ;

Crepicephalus chares n. sp. (Ptarmigan), pl. 6, figs. 5, 5a-c

Vanuxemella contracta Walcott (Gordon) (Smithsonian Misc. Coll., Vol. 64,
1916, p. 221, pl. 36, figs. 4, 4a)

Vanusxemella nortia Walcott (Idem, p. 222), pl. 7, fig. 7

Olenopsis americanus Walcott (Gordon) (Idem, Vol. 57, p. 243, pl. 36,
figs. 8-11) .

Olenopsis cf. americanus Walcott (Idem), pl. 6, figs. 8, 8a-b

Albertella boswortht Walcott (Idem, Vol. 53, 1908, p. 22), pl. 7, figs. 2, 2a-b,
3, 3a-d

Albertella helena Walcott (Idem, p. 19), pl. 7, figs. 4, 5, 5a

Albertella levis n. sp. (Chetang), pl. 7, figs. 1, 1a

Zacanthoides charilla n. sp. (Chetang), pl. 6, figs. 9, 9a

Zacanthoides ? cimon n. sp. (Ptarmigan), pl. 7, figs. 6, 6a

Zacanthoides cnopus n. sp. (Gordon), pl. 6, figs. 10, Toa

Neolenus constans n. sp. (Ptarmigan), pl. 6, figs. 7, 7a

Bathyuriscus belesis Walcott (Gordon) (Smithsonian Misc. Coll. Vol. 64,
I916, p. 338, pl. 50, figs. 1, Ia-1)

Bathyuriscus belus Walcott (Gordon) (Idem, p. 339, pl. 50, figs. 2, 2a-d)

Bathyuriscus yossensis n. sp., pl. 5, figs. 5, 5a-d

Bathyuriscus cf. rossensis n. sp., pl. 5, figs. 6, 6a

Bathyuriscus (Poliella) chilo n. sp. (Ptarmigan), pl. 5, fig. 4

Bathyuriscus (Polhella) sylla Walcott (Chetang) (Smithsonian Misc. Coll.
“Vol. 64, 1916, p. 354, pl. 48, figs. 3, 3a-f)

The fauna of the Gordon shale in Montana includes (4q, 4v):

Algze
*Hyolithes cf. cecrops Walcott
Micromitra (Iphidella) nyssa Walcott
Micromitra (Iphidella) pannula (White)
Obolus (Westoma) ella (Hall and Whitfield)
Lingulella sp. undt.
*Acrothele collent Walcott
Acrothele pandert Walcott
*Wimanella simplex Walcott
Ptychoparia candace Walcott
Ptychoparia charax Walcott
Ptychoparia pylas Walcott
*Olenopsis americanus Walcott
*Albertella helena Walcott
Bathyuriscus belesis Walcott
*Vanuxemella contracta Walcott
Zacanthoides cnopus Walcott

* The species common to the Gordon shale and the Ross Lake shale are
marked by an asterisk.

24 MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

From the Chetang formation only six species were collected :

Nisusia cf. alberta Walcott

Albertella bosworthi Walcott

Albertella levis Walcott

Agraulos cf. stator Walcott

Zacanthoides charilla Walcott ;
Bathyuriscus (Poliella) sylla Walcott

The Ptarmigan formation limestones have yielded but six species:

Ptychoparia cilles Walcott
Crepicephalus chares Walcott
Albertella bosworthi Walcott
Zacanthoides ? cimon Walcott
Neolenus constans Walcott
Bathyuriscus (Poliella) chilo Walcott

DESCRIPTION OF GENERA AND SPECIES
THOLIASTERELLA Hinde

Tholiasterella H1inbE, 1888, Monogr. British Fossil Sponges, Pal. Soc., Lon-
don, Pt. II, p. 168. (Described and discussed. )

Dr. Hinde describes the sponge spicules referred to this genus as
follows:

Form of Sponge unknown; the skeleton consists of spicules, which . . . bear
a general resemblance to the handle and ribs of an umbrella. The handle or
vertical ray of the spicule supports on its summit a variable number of rays
which radiate from it in a generally horizontal direction. A central disc of
variable proportions is formed by the union of the bases of the horizontal rays
and the upper surface of this, and of the rays, may be either smooth or
covered with tubercles or blunted vertical spines.

Dr. Zittel, in speaking of the genus, says: “As a rule, two of
the rays lying in the same plane divide dichotomously from the nodes
outward, so as to produce a six-armed instead of a four-armed
cross.” *

Stratigraphic range—Carboniferous.

It is not probable that the Middle Cambrian species now described
belongs in this genus, but with only the spicules flattened in the
shale for comparison it does not seem best to found a new genus for
them. The six-rayed spicule with a central nodule suggests some
forms of the spicules referred to Tholiasterella. They appear to be
more nearly related to the latter than to the spicules of Astre-
ospongia Roemer from the Silurian.’

* Text-book Pal., edited by Eastman, Vol. 1, 1913, p. 62.
* As defined by Hinde. Fossil Sponges, pp. 133-134, pl. 1, figs. 7, 7a-d.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 25

THOLIASTERELLA ? HINDEI, new species
Plate 4, figs. I, Ia

Six-rayed spicules with a central canal in the rays, a tubercle where
the ray merges into the central disc of the spicule, also a central
tubercle which suggests that it may have been the base of a central
ray or shaft.

There is a trace of longitudinal, raised lines on one of the arms.
The type spicule measures 16 mm. from tip to tip of opposite rays.

The original substance of the spicule has been replaced by the dark
siliceous sediment forming the shale.

The doubtful character of the generic reference is mentioned in
the note on the genus.

Formation and locality—Middle Cambrian: (63}]) Ross Lake
shale member of the Ptarmigan formation; cliffs above Ross Lake
1.5 miles (2.4 km.) south-southwest of Stephen on the Canadian
Pacific Railway, British Columbia, Canada.

EOCYSTITES ? species undetermined
Plate 4, fig. 2

A single crushed specimen of the calyx and arms of this species
is all that is known of it. There is not sufficient evidence on which
to base an accurate generic and much less a specific determination.

Formation and locality—Middle Cambrian: (63j) Ptarmigan
formation, Ross Lake shale; outlet of cirque above and south of
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway, British Columbia,
Canada.

BRACHIOPODA

MICROMITRA (PATERINA) WAPTA Walcott
Plate 4, fig. 3
Micromitra (Paterina) wapta Watcott, 1912. (See Monogr. 51, U. S.
Geol. Surv., 1912, p. 357, text figs. 29, A, B.)
OBOLUS PARVUS Walcott
Plate 4, figs. 4, 4a
Obolus parvus Watcortt, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912,
p. 408, text figs. 37, A, B.)
ACROTHELE COLLENI Walcott
Plate 4, figs. 5, 5a-f

Acrothele colleni Wavcort, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912,
p. 640, text figs. 55, A-E; pl. 63, figs. 6, 6a-b.)

26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

WIMANELLA SIMPLEX Walcott
Plate 4, figs. 6, 6a-c, 7, 7a-c, 8, 8a-c

Wimanella simplex Watcott, 1912. (See Monogr. 51, U. S. Geol. Surv.,
1912, p. 748, text fig. 64; pl. 80, figs. 2, 2a-e.)

NISUSIA cf. ALBERTA Walcott
Plate 4, fig. 9
Nisusia alberta Wa.cott, 1889. (See Monogr. 51, U. S. Geol. Surv., 1912,
p. 720, pl. 100, figs. 3, 3a-d.)

Only one small ventral valve of this type has been found in the
Chetang limestone. It is strikingly similar to the small shells referred
to Nisusia alberta as found in the shales and limestones of the central
and lower portions of the Stephen formation at Mount Stephen,
British Columbia.

The narrow, rather strong radiating ribs with nodes on them indi-
cating spines and minute pores penetrating some of the layers of the
shell indicate the genus Nisusia.

Formation and locality —Middle Cambrian: (610) Chetang for-
mation ; gray shaly limestone in massive beds; on northeast slope of
Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.)
north-northeast in direct line from summit of Robson Peak, north-
west of Yellowhead Pass, western Alberta, Canada.

HYOLITHELLUS FLAGELLUM (Matthew)
Plate 5, figs. 2, 2a

Urotheca flagellum Matruew, 1899, Trans. Roy. Soc. Can., 2d ser., Vol. 5
Sec. 4, p. 40, pl. 1, fig. 1. (Species described and figured.)

Hyolithellus fagellum WW aAucort, 1908, Canadian Alpine Journ., Vol. 1, No. 2,
p. 14, pl. 31, figs. 8, 8a. (Changes generic reference and illustrates
species. )

This species is represented in the collection by four small tubes
that appear to have been attached to the dorsal valve of Wimanella
simplex. The specimens are not very well preserved and it may be
that they are the young or small tubes of H. annulatus (Matthew ).

Formation and locality—Middle Cambrian: (63j]) Ptarmigan
formation; Ross Lake shale; outlet of cirque above and south of
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway, British Columbia,
Canada.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 27

HYOLITHELLUS HECTORI, new species
Plate 5, fig. 1

This species is represented by a single specimen of a slender, rather
thick tube, about 1 mm. in diameter, of which a portion 21 mm. in
length is preserved. The tube has the form of the tube of Hyoli-
thellus flagellum (pl. 5, fig. 4), but it is thicker and its surface is
longitudinally ribbed by 24 or more narrow, sharp elevated lines or
ribs ; exceedingly fine transverse striz of growth also occur between
the crests of the ribs. A somewhat similar surface occurs on
Hyolithes (Orthotheca) rosmarus Holm* and on Hyolithes cym-
bium Holm.’

Formation and locality—Middle Cambrian: (35c) Ptarmigan
formation ; Ross Lake shale, Albertella zone ; drift blocks of siliceous
shale from the Ptarmigan formation, found on the south slope of
Mount Bosworth, about 500 feet (152 m.) northwest of the Canadian
Pacific Railway track between Stephen and Hector, eastern British
Columbia, Canada.

HYOLITHES CECROPS, new species
Plate 5, figs. 3, 3a-c

Shell nearly if not quite straight; the angle of divergence of the
lateral borders from the median line is from 12 to 14 degrees. The
dorsal side gently arched or nearly flat. Ventral side rising from the
lateral borders to a rounded angle at the median line. The trans-
verse section forms a triangle, with the base two or three times
as great as the height. Surface of shell with very fine transverse
strie and rather distinct lines of growth.

Dimensions.—A large shell has a length of 40 mm. with a breadth
of the mouth of 16mm. Another has a length of 42 mm.; breadth at
the mouth, 13 mm. A small shell, 15 mm. in length, has a breadth
at the mouth of 8 mm., but it has been shortened and widened by
distortion in the shale. The specimen 42 mm. long and 13 mm. wide
at the mouth is probably the nearest to the original size of the shell.

Operculum.—The associated operculum is illustrated by figure 3c.
Although the shells are abundant, only three specimens of the oper-
culum have been found.

Observations —This species is uniformly larger than Hyolithes
billingst of the Mount Whyte formation, and has a more triangular

*Sveriges Geol. Undersdkning, Ser. C, No. 112, 1893, Sv.-Kambrisk.-
Siluriska Hyolithidz och Conularide, pl. 1, figs. 45, 46.
* Idem, pl. 3, fig. 7.

28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

section. It differs from Hyolithes carinatus Matthew of the Stephen
formation in absence of longitudinal ridges on the ventral side and
also in its more triangular section.

Formation and locality—Middle Cambrian: Ross Lake shale
member of Ptarmigan formation; (63j) outlet of cirque above and
south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.)
south-southwest of Stephen on Canadian Pacific Railway; (63m) _
south slope of Mount Bosworth, about 500 feet (152.4 m.) above the
Canadian Pacific Railway track, 1 mile (1.6 km.) east of Hector,
1.25 miles (2 km.) west of Stephen on the Continental Divide;
(35c) drift boulder below locality 63m, all in British Columbia,
Canada.

AGRAULOS STATOR Walcott
Plate 6, fig. 6

Agraulos stator Watcott, 1916, Smithsonian Misc. Coll., Vol. 64, p. 173,
pl. 36, fig. 6. (Described and illustrated.)

This very neat and fine species is quite abundant in some localities
of the Ross Lake shale.

(63j]) Ptarmigan
formation; Ross Lake shale; outlet of cirque above and south of
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway; also (35c)
drift blocks of siliceous shale from the Ptarmigan formation, found
on the south slope of Mount Bosworth, about 500 feet (152 m.)
northwest of the Canadian Pacific Railway track between Stephen
and Hector, eastern British Columbia, Canada.

An apparently similar species as far as can be detenmniiel from
the cranidium occurs in the limestone of the Chetang formation:
(61w) gray, thin-bedded limestone; float rock in Terrace Creek,
the head of which comes from Terrace Glacier, which joins Cole-
man Glacier on the divide east of Chetang Cliffs. Terrace Creek
enters Moose River about 6 miles (9.6 km.) below Moose Pass and
10 miles (16.1 km.) east-northeast of Robson Peak, northwest of
Yellowhead Pass, eastern British Columbia, Canada.

PTYCHOPARIA CANDACE, new species
Plate 6, figs. 3, 3a ¢

Dorsal shield —Dorsal shield rather small but strong. Axial lobe
relatively broad, and doubtless strongly arched before compression ;

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 29
greatest width probably falling a little in front of the thorax and
equal to a little less than two-thirds of the length.

Cephalon.—Cranidium only preserved. Glabella moderately large
relatively, elongate trapezoidal; dorsal furrows moderately im-
pressed, converging so rapidly that the width in front is but little
more than half of that of the base; anterior extremity of the glabella
broadly rounded or obscurely truncate ; glabellar furrows broadened
or deepened by compression in the somewhat flattened cranidium
figured ; posterior furrows oblique, posteriorly directed, medial pair
somewhat cuneate, the anterior margin of the furrow at right angles
to the axis of the shield, the posterior margin oblique ; anterior pair
of furrows also cuneate but anteriorly directed, the lobe between the
anterior and medial furrows with parallel sides at right angles to
the axis; occipital furrow quite deeply impressed distally but almost
obsolete upon the crest of the glabella; occipital ring expanded
medially and bearing a rather large median node. Fixed cheeks low
and quite broad, the distance from the palpebral lobe to the dorsal
furrow more than half the width of the medial portion of the glabella ;
postero-lateral lobe very broad, trigonal in outline, the distal extrem-
ity tapering to an angle of about 45°; posterior groove broad but
not very deep. Palpebral lobe very short, not very prominent,
placed far forward opposite the anterior glabellar furrows. Palpe-
bral ridge cordate, moderately elevated, cutting across the fixed
cheeks almost at right angles to the shield, and intercepting the
dorsal furrows about half-way between the anterior glabellar furrows
and the anterior extremity. Frontal limb rather wide, probably
evenly sloping before compression. Frontal border almost as wide
medially as the medial portion of the limb and cut off from it by a
shallow groove. Facial sutures angular, the posterior arm oblique,
the anterior arm feebly convex; arc included between the facial
sutures almost double the width of the base of the glabella. Free
cheeks not preserved.

Thorax.—Thorax rather slender, tapering posteriorly. Thoracic
segments 16 in number. Axial lobe flattened in the shale and rela-
tively very broad, as a rule, decidedly more than half as wide as
either of the pleural lobes; axial annulations conspicuously coarse.
Pleural segments rather narrow, compactly arranged, obtusely angu-
lated at the geniculation which falls about two-thirds of the distance
from the axial furrow to the outer extremity ; pleural furrows broad
and rather shallow for the most part, narrower and much deeper

30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

toward the distal extremity; ends of segments feebly inclined
posteriorly and acutely falcate.

Pygidium.—Pygidium very short, only about one-eighth the length
of the entire shield, rudely lenticular in outline. Axial lobe coarse,
wider than either of the pleural segments, becoming increasingly
lower posteriorly but persisting almost to the extremity ; axial annula-
tions very obscure anteriorly, obsolete medially and posteriorly ;
component segments probably 4 or 5 in number. ‘Pleural lobes
trigonal, bearing traces anteriorly of an obscure grooving. Periph-
eral rim not defined. Peripheral margin an arc of a little less than
180°.

Surface.—Surface ornamentation lost or undeveloped.

Dimensions.—Length of shield, 12.5 mm.; greatest width of
shield, 8.0 mm.

Type locality —(4v) Gordon Creek, Powell County, Montana.

Observations—The elongate body, small pygidium and small
palpebral lobe all suggest A graulos stator Walcott,’ but the cranidium
is that of Ptychoparia and there are 16 thoracic segments, while
A, stator has 22. P. candace appears to be a form that unites strong
characters both of Agraulos and Ptychoparia.

It differs from Ptychoparia perola of the subjacent Mount Whyte
formation of British Columbia in details of the cranidium and in its
broader thoracic lobes; its glabella is more elongate, frontal limb
deeper, palpebral lobe larger. The largest dorsal shield has a length
of 20mm. A small dorsal shield 2.25 mm. in length has 1o thoracic
segments and the cranidium indicates a narrowing of the elabellar
lobe and widening of the fixed cheeks back of the palpebral lobes.
The specimens occur in an argillaceous shale and do not retain the
original surface characters. Ptychoparia candace is found in the
Albertella fauna of Montana but not in that fauna in British
Columbia. The genus is represented in the latter area by Ptycho-
paria ? cilles, which is quite distinct.

*Smithsonian Misc. Coll., Vol. 64, p. 173, pl. 36, fig. 6. See p. 28, and pl. 6,
fig. 6, this paper.

NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 31

PTYCHOPARIA ? CHARAX, new species
Plate 6, fig. 1

Species known only from two cranidia.

Cephalon.—Glabella rather small relatively, not much more than -
half as long as the cranidium, low, elongate, trapezoidal in outline,
the front between one-half and two-thirds as wide as the base; dorsal
furrows moderately impressed, evenly converging toward the broadly
rounded anterior extremity; glabellar furrows rather broad and
obscure, obsolete medially ; posterior pair somewhat oblique ; medial
pair approximately horizontal; anterior pair indicated merely by very
feeble depressions a little behind the anterior extremity ; occipital
furrow rather broad but not very deep, approximately uniform in
depth between the dorsal furrows; occipital ring not very wide,
expanding medially, possibly bearing a small medial node. Fixed
cheeks rather low, broad, the distance from the palpebral lobe to the
dorsal furrow a little more than half as wide as the medial portion
of the glabella ; postero-lateral lobe narrow, not very long, cuneate,
acutely rounded at the distal extremity ; posterior groove broad and
sharply defined excepting near the dorsal furrow, widest a little less
than half-way from the inner to the outer extremity ; posterior margin
of the lobe narrow, elevated, uniform in width; anterior margin of
the groove acute, excepting along the inner third of its extent, rudely
bisecting the outer cuneate portion of the lobe. Frontal limb and
border not sharply differentiated from one another, upturned and
slightly thickened along the outer rim; width of limb and border
in front of the glabella about three-fifths the length of the glabella;
profile gently concave medially, convexo-concave in front of the
palpebral ridge. Palpebral lobe approximately one-half as long
as the glabella, obliquely arcuate, quite prominently elevated, placed
quite far back, so that the medial portion of the lobe is opposite the
posterior glabellar furrows. Palpebral ridge not sharply differen-
tiated from the lobe, cutting obliquely across the fixed cheeks from the
anterior extremity of the lobe, and intercepting the dorsal furrows a
little behind the anterior extremity of the glabella. Facial sutures
irregular in outline, the posterior section oblique, the outer margin
of the palpebral lobe asymmetrically arcuate and the anterior section
conspicuously broad and evenly convex. Other characters not
preserved.

Surface External surface shagreened with an exceedingly fine
punctation.

32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Dimensions—Length of cranidium, 9.6 mm. Length of glabella,
6.0mm. Width of anterior extremity of the glabella, 3.0mm. Width
of base of the glabella, 5.0 mm.

Type locality—(4v) Gordon Creek, Montana.

Observations.—This is one of the Ptychoparia-like cranidia with
a broad concave frontal border and rim that will undoubtedly be
placed in a subgenus of Ptychoparia when the American species of
the latter genus are clearly studied. The genus Agraulos is sug-
gested, but that is forcing a form in that genus that apparently
belongs elsewhere.

Formation and locality—Middle Cambrian: (4v) Gordon shale;
about 200 feet (61 m.) above the unconformable base of the Cambrian
and 75 feet (22.9 m.) above the top of the quartzitic sandstones,
Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River ;
and (4q) about 315 feet (96 m.) above the unconformable base of
the Cambrian and 190 feet (57.9 m.) above the top of the quartzitic
sandstones in a shale on the ridge between Gordon and Youngs
Creeks, about half-way between Gordon Mountain and Cardinal
Peak, both in Ovando quadrangle (U. S. G. S.), Powell me:
Montana.

PTYCHOPARIA ? CILLES, new species
Plate 6, fig. 2

Species known only from imperfect cranidia.

Cephalon.—Cranidium very strongly contoured. Glabella con-
spicuously elevated, approximately two-thirds the length of the
cranidium and as broad at the base as it is long ; medial section broad
and obtuse, very gradually disappearing toward the anterior ex-
tremity ; dorsal furrows very obscurely defined, converging so rapidly
that the broadly rounded anterior extremity is only half as wide
as the base; glabellar furrows sharply impressed upon the sides of
the glabella but obsolete upon the crest; posterior pair cuneate,
widening toward the crest, obliquely directed ; medial pair not quite
so broad nor so oblique; anterior pair linear but deeply incised at
right angles to the axis of the shield; occipital furrow rather broad,
extending across the crest of the glabella but deepening toward the
dorsal furrows; occipital ring imperfectly preserved, expanded
medially, and probably of moderate width. Fixed cheeks rising
abruptly to almost the level of the summit of the glabella, the slope
from the dorsal furrow to the crest of the glabella very similar to the
slope from the dorsal furrow to the palpebral lobe; postero-lateral

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 33

lobe almost if not quite as broad as it is long, obtuse at the outer
extremity ; postero-lateral groove narrow toward the axis and in line
with the occipital groove, broadening and deepening away from the
axis. Palpebral lobe small but conspicuously high, arcuate, placed far
forward opposite the lobe between the medial and anterior glabellar
furrows. Palpebral ridge very narrow and rather obscure, forming
an acute angle with the anterior extremity of the palpebral lobe, and
slightly inclined posteriorly in crossing the fixed cheek so that it
intercepts the dorsal furrows near the origin of the anterior glabellar
furrows. Frontal limb narrow, feebly convex in front of the glabella
and merging into the frontal border which is as wide or wider than
the limb, and very strongly upturned so that the outline of the
anterior portion of the cranidium is decidedly concave. Facial
sutures following a sine curve from the genal angle along the
anterior margin of the postero-lateral lobe to the eye lobe; anterior
section of the suture more strongly convex than the posterior. A
single imperfectly preserved free cheek, terminating in a rather
short but acutely tapering spine, is associated with the cranidia.

Surface —External surface microscopically shagreened.

Dimensions.—Length of cephalon, 3.0 mm. Length of glabella,
2.0 mm.

Type locality—(63d) Ptarmigan formation; Ptarmigan Peak.

Observations —This small species is quite distinct from any other
known to me. Its high eyes, concave frontal border and convex,
strongly marked glabella distinguish it and also indicate a distinct
subgenus or genus.

Formation and locality—Muiddle Cambrian: (63d) Ptarmigan
formation ; dark, thin-bedded finely arenaceous limestone, east base
of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of
Lake Louise Station on the Canadian Pacific Railway, Alberta,
Canada.

PTYCHOPARIA PYLAS, new species
Plate 6, figs. 4, 4a-c

Dorsal shield—Dorsal shield rather small, elongate oval or cuneate
in outline, doubtless quite strongly contoured before being com-
pressed in the shale.

Cephalon.—Head shield exclusive of the genal spines approxi-
mately one-third of the length of the dorsal shield, and a little less
than twice as broad as it is long. Glabella angular, elongate-
trapezodial in outline; only about half as wide at the anterior ex-

34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

tremity as it is at the base; dorsal furrows deeply impressed, inter-
cepting the frontal furrow at an acute angle; glabellar furrows
very obscure but persistent, in some individuals, across the crest of
the glabella; posterior and medial pairs oblique and approximately
parallel to one another, the anterior pair shorter, transverse to the
axis, and in some individuals apparently undeveloped; occipital
furrow broad and conspicuously deep, in most individuals, com-
pletely isolating the occipital ring ; occipital ring similar in character
to the anterior segments of the thorax, probably not spinose medially.
Fixed cheeks quite wide and rather plump; postero-lateral lobe
narrow, moderately produced, angulated at the outer extremity ;
posterior groove narrow, deeply impressed, in line with the occipital
furrow; posterior margin sharply elevated. Palpebral lobe large,
conspicuously elevated, quite strongly crescentic. Palpebral ridge
not sharply differentiated from the lobe as a rule, cutting across the
fixed cheek almost at right angles to the axis and almost in line with
the anterior furrow, and forming with the palpebral lobes and the
anterior furrow of the glabella a rudely elliptical area. Frontal limb
quite wide, evenly declining, or more frequently somewhat convex
especially towards the sides. Frontal border moderately wide, not
thickened, upturned, cut off from the limb by a shallow, ill-defined
groove. Facial sutures roughly a spreading W with a broad arcuate
base, a rather long, oblique, posterior limb and a rather short, convex,
anterior limb. Free cheeks quite wide and smoothly inflated, the
outer margin flattened and produced posteriorly into acutely tapering
genal spines which terminate opposite the third thoracic segment.
Thorax.—Thoracic segments probably 14 in number. Axial lobe
quite prominent, moderately broad, cut off from the pleura by deep
furrows. Pleural segments flexuous, even in the shale, obtusely
angulated at the geniculation which falls, in the majority of indi-
viduals, a little less than half-way from the proximal to the distal
extremity ; pleural furrows very narrow and deeply incised, ‘sub-
medial in position. Ends of segments cut away along the posterior
margin, slightly inclined posteriorly, and acutely falcate.
Pygidium.—Pygidium very small and very imperfectly known.
Surface.—Character of external surface not preserved.
Dimensions,—Length of dorsal shield, 4.7 mm. Greatest width of
dorsal shield, 3.2 mm. Length of the cranidium of another indi-
vidual, 6.5mm. Length of glabella, 4.0 mm.
Type locality—(4q) Gordon Creek, Montana.

NO. 2 ALBERTELLA FAUNA IN. BRITISH COLUMBIA AND MONTANA 35

Observations.—This species is strongly characterized by its small
pygidium, straight, deep pleural grooves on the thoracic segments,
and broad frontal limb of the cranidium.

Formation of locality—Middle Cambrian: (4q) Gordon shale;
about 315 feet (96 m.) above the unconformable base of the Cam-
brian and 190 feet (57.9 m.) above the top of the quartzitic sand-
stones in a shale on the ridge between Gordon and Youngs Creeks,
about half-way between Gordon Mountain and Cardinal Peak, both
in Ovando quadrangle (U.S. G.S.), Powell County, Montana.

CREPICEPHALUS CHARES, new species
Plate 6, figs. 5, 5a-c

Species known only from a few imperfect cranidia and associated
pygidia.

Cephalon.—Cephalon as restored from cranidium and free cheeks
rather short and broad. Glabella a little less than two-thirds the
length of the cranidium, low and moderately broad, rudely trape-
zoidal in outline, elevated along an obscure medial ridge which
gradually disappears toward the front; dorsal furrows not sharply
defined, converging toward the squarely truncate anterior extremity
with such rapidity that the front of the glabella is only half as wide
as the base; glabellar furrows also rather obscure and, upon the
crest of the glabella, entirely obsolete; posterior pair rather broad,
obliquely directed ; medial and anterior pairs also rather broad and
almost at right angles to the axis; occipital furrow of the same
general character as the glabellar furrows, not very deep but mni-
formly impressed throughout its extent; occipital ring of only
moderate width, expanded medially and possibly obtusely angulated
along the posterior margin. Fixed cheeks very low and broad, the
distance from the palpebral lobe to the dorsal furrows more than
half the width of the medial portion of the glabella; more strongly
convex along the axis of the shield than at right angles to it ; postero-
lateral lobe not preserved but necessarily narrow; groove in front
of the posterior margin shallow toward the axis and in line with the
occipital ring. Palpebral lobe imperfectly preserved, apparently
short, crescentic, rather low and placed far back opposite the pos-
terior lobe and furrow. Palpebral ridge cordate, moderately ele-
vated, curving across the fixed cheek from the anterior extremity of
the eye lobe and intercepting the dorsal furrows a little behind the
anterior extremity of the glabella; palpebral ridges and lobes form-
ing roughly a semi-ellipse interrupted by the glabella. Frontal limb

36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

moderately wide, gently convex. Frontal border almost as wide as
the limb, gently concave. Facial sutures very imperfectly preserved.
Associated free cheek rather narrow, smoothly convex; peripheral
border very wide and flattened, terminating posteriorly in a rather
short but acute spine.

Pygidium.—Associated pygidium rudely cordate in outline, exclu-
sive of the posterior constriction, the length and breadth approxi-
mately equal. Axial lobe not quite half as long as the caudal shield
including the spines, but approximately two-thirds the length
measured along the axis; limiting furrows not impressed, the lobe
differentiated only by its low convexity and the rather obscure annula-
tion; component segments apparently five in number including the
terminal section. Pleural lobes somewhat flexuous, broadest a little
in front of the median line, produced posteriorly into a pair of acute
subspinose processes; margin between these tapering extremities
sharply constricted. Pleural furrows ill defined; three or four
shallow grooves usually developed parallel to the outer margin,
least obscure anteriorly but on the posterior portion of the shield
entirely obsolete. Peripheral margin very slightly raised anteriorly,
not differentiated from the rest of the shield posteriorly.

Surface—Entire external surface crowded with a fine granula-
tion; very sparse macroscopic granulation also developed on the
cephalon and less so on the pygidium; granules most numerous and
most regularly arranged upon the frontal border.

Dimensions.—Length of cephalon, 8.5 mm. Length of glabella,
5.0mm. Width of glabella at base, 4.6 mm. Length of pygidium,
including spines, 5.6+ mm. Length of pygidium, excluding spines,
3.7mm. Breadth of pygidium, 5.6 mm.

Type locality —(63d) Ptarmigan formation; Ptarmigan Peak.

Observations—The most nearly related species appears to be
Crepicephalus camiro Walcott.’ It differs from the latter in the
details of form of the various parts of the cranidium and associated
pygidium and in its granulated surface. C.camiro is from the Upper
Cambrian of the southern Appalachian area and C. chares is from
the Middle Cambrian of the Canadian Rocky Mountains.

The cranidium of C. cleora, a new species from the Mount Whyte
formation, is much like that of C. camiro but differs in its wider
frontal border and other details of the cranidium.

Formation and locality—Middle Cambrian: (63d) Ptarmigan
formation; dark, thin-bedded finely arenaceous limestone, east base

* Smithsonian Misc. Coll., Vol. 64, 1916, p. 205, pl. 32, figs. 2, 2a.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 37

of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of
Lake Louise Station on the Canadian Pacific Railway, Alberta,
Canada.
VANUXEMELLA NORTIA Walcott
Plate 7, fig. 7

Vanuxemella nortia Wat.cott, 1916, Smithsonian Misc. Coll., Vol. 64, p. 222,

pl. 36, fig. 5. (Described and illustrated.)

Nothing has been added to our information of this species by
recent collections.

Formation and locality—Middle Cambrian: (63j) Ptarmigan
formation; Ross Lake shale; outlet of cirque above and south of
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway, British Col-
umbia ; and (35c) drift blocks of siliceous shale from the Ptarmigan
formation, found on the south slope of Mount Bosworth, about 500
feet (152 m.) northwest of the Canadian Pacific Railway track
between Stephen and Hector, eastern British Columbia, both in
Canada.

OLENOPSIS cf. AMERICANUS Walcott

Plate 6, figs. 8, 8a-b

Olenopsis americanus WA.cottT, 1912, Smithsonian Misc. Coll., Vol. 57, p. 243,

pl. 36, figs. 8-11. (Description and illustration of species. )

Cranidia that appear to be identical with the cranidium of this
species occur in association with Albertella helena in British
Columbia, and the latter species is also associated with the type
specimen of Olenopsis americanus in the Gordon shale of Montana.

Formation and locality —Middle Cambrian: (63j) Ptarmigan for-
mation ; Ross Lake shale; outlet of cirque above and south of Ross
Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway; also (35c)
Albertella shale; drift blocks of siliceous shale from the Ptarmigan
formation, found on the south slope of Mount Bosworth about 500
feet (152 m.) northwest of the Canadian Pacific Railway track
between Stephen and Hector, eastern British Columbia, Canada.

The Montana locality of the type specimens of the species is (4v)
Middle Cambrian ; Gordon shale; about 200 feet (61 m.) above the
unconformable base of the Cambrian and 75 feet (22.9 m.) above the
top of the quartzitic sandstones, in a shale which corresponds in
stratigraphic position to shale No. 6 of the Dearborn River section,’

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 202.

38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River,
Ovando quadrangle (U.S. G. S.), Powell County, Montana.

ALBERTELLA BOSWORTHI Walcott
Plate 7, figs. 2, 2a-b, 3, 3a-d

Albertella bosworthi WWaxcott, 1908, Smithsonian Misc. Coll., Vol. 53, p. 22,
pl. 1, Ags. 4-7. (Description and illustration of the species.)

Albertella bosworthi Watcort, 1913, The Cambrian Faunas of China, Pub.
No. 54, Carnegie Inst. of Washington, p. 105, pl. 12, fig. 2. (Figured on
same plate with A. pacifica for purpose of comparison.)

The type specimen of this species was found in a drift boulder
on the slopes of Mount Bosworth. Since 1908 entire specimens of
the species have been found in situ on Mount Bosworth, also above
Ross Lake south of Mount Bosworth and represented by fragments
in the limestones of Castle Mountain, British Columbia, and in the
Robson District of Alberta and British Columbia.

The specimens of the cranidium and pygidium from the limestones
(figs. 3, 3b) are more convex and narrower than those from the
shale in the Mount Bosworth area, owing to their not having been
widened and distorted by compression as are the shale specimens.

Formation and locality—Middle Cambrian: Ptarmigan forma- —
tion; Ross Lake shale; (63j) outlet of cirque above and south of ©
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway; (35¢) drift
blocks of siliceous shale from the Ptarmigan formation, found on
the south slope of Mount Bosworth, about 500 feet (152 m.) north-
west of the Canadian Pacific Railway track between Stephen and
Hector; also (63m) Ross Lake shale; south slope of Mount Bos-
worth, about 500 feet (152 m.) above the Canadian Pacific Railway
track, 1 mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west
of Stephen on Continental Divide, all in British Columbia, Canada.

At the locality 63m the species was found in thin layers of lime-
stone interbedded in the shale: (58h) about 275 feet (85 m.)
above the top of the Lower Cambrian in thin-bedded bluish-black
limestone (272 feet=84 m.) forming 13 in Ptarmigan formation,
Castle Mountain section ; just below the big cliff on the east shoulder
of Castle Mountain, north of Canadian Pacific Railway, Alberta,
Canada.

Also from (61p) Chetang formation; gray shaly limestone in
massive beds; on northeast slope of Chetang Cliffs above Coleman
Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 39

summit of Robson Peak, northwest of Yellowhead Pass, western
Alberta, Canada.

ALBERTELLA HELENA Walcott
Plate 7, figs. 4, 5, 5a

Albertella helena Watcott, 1908, Smithsonian Misc. Coll., Vol. 53, p. 19, pl. 2,
figs. 1-9. (Description and illustration of species.)

Albertella helena GraBau and SHIMER, 1910, North American Index Fos.,
Vol. 2, p. 274, fig. 1572c. (Characterized and figured.)

Albertella helena Waucott, 1913, The Cambrian Faunas of China, Pub.
No. 54, Carnegie Inst. of Washington, p. 106, pl. 12, fig. 1. (Figured on
same plate with A. pacifica for purpose of comparison.)

This species was described at length in 1908. Recent collections

have added very little to the information about it.

Formation and locality—-Middle Cambrian: (63j) Ptarmigan
formation; Ross Lake shale; outlet of cirque above and south of
Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-
southwest of Stephen on Canadian Pacific Railway; (35c) Drift
blocks of siliceous shale from the Ptarmigan formation, found on
the south slope of Mount Bosworth, about 500 feet (152 m.) north-
west of the Canadian Pacific Railway track between Stephen and
Hector; and (63m) Ross Lake shale; south slope of Mount Bos-
worth, about 500 feet (152 m.) above the Canadian Pacific Railway
track, I mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west
of Stephen on Continental Divide, all in British Columbia, Canada.

ALBERTELLA LEVIS, new species
Plate 7, figs. 1, 1a

This species is represented by the cranidium and associated pygi-
dium. The cranidium differs from that of A. bosworthi by its
glabella being more expanded towards the front, much fainter
glabellar furrows, relatively shorter palpebral lobes and almost
smooth instead of finely granulated outer surface of the test. A
minute median node occurs near the posterior margin of the occipital
ring in both A. levis and A. bosworthi. .

The pygidium associated with the cranidia, also the cranidium
and pygidium of A. bosworthi, in two blocks of limestone, are quite
unlike the pygidia of typical Albertella, as the two spines emerge
from the border at the postero-lateral margins and the pygidium
is wider posteriorly and shorter. The axial lobe is narrow, strongly
convex and with five segments and a terminal section; pleural lobes
marked by three slightly impressed narrow furrows.

40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Surface of cranidium and pygidium smooth except when a strong
lens is used to bring out a very fine irregular, closely inosculating
series of ridges.

The largest cranidium has a length of 7.5 mm.

Formation and locality—Middle Cambrian: (61p) Chetang for-
mation ; gray shaly limestone in massive beds, on northeast slope of
Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.)
north-northeast in direct line from summit of Robson Peak, north-
west of Yellowhead Pass, western Alberta, Canada.

ZACANTHOIDES CHARILLA, new species
Plate 6, figs. 9, 9a

Species known only from an imperfect cranidium and from two
pygidia.

Cephalon.—Glabella large relative to the size of the cranidium,
broadest anteriorly, gradually contracting toward the rather slender
base, slightly expanding at the occipital ring, broadly and feebly
arched, the curvature greatest a little in front of the median line;
dorsal furrows quite deeply impressed, slightly concave, most strongly
constricted opposite the posterior lobe; anterior extremity broadly
arcuate; posterior glabellar furrows linear, converging toward the
occipital groove, obsolete upon the summit of the glabella; medial
glabellar furrows suggested by a very shallow and obscure depression
extending across the glabella at right angles to the axis, about half
way between the anterior extremity and the occipital ring; anterior
glabellar furrows even more obscure than the medial, directed for-
ward, but entirely obsolete upon the summit of the glabella ; occipital
groove moderately wide, uniform in depth between the dorsal fur-
rows; occipital ring quite wide and flattened. Fixed cheeks very
much reduced; the area between the eye lobe and the dorsal furrow
not much greater than the lobe; postero-lateral lobe very narrow,
deeply furrowed in front of the posterior margin; outer extremity
of lobe not preserved. Anterior limb very narrow and merging into
the antero-lateral margin of the glabella; frontal limb obsolete,
frontal border a narrow wire-like rim. Palpebral lobe very large,
approximately half as long as the glabella, feebly arcuate, quite
prominently elevated, cut off from the fixed cheek by a shallow
groove; posterior extremity of the eye lobe opposite the posterior
lobe of the glabella, the anterior extremity of the eye lobe intercept-

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 4I

ing the dorsal furrows at the origin of the anterior glabellar furrows.
Other characters of the cephalon not preserved.

Pygidium.—Associated pygidium rather large for the cephalon,
trigonal in outline, exclusive of the peripheral fringe of spines.
Axial lobe decidedly wider than the pleural exclusive of their spinose
annulations rather coarse, obscure only near the posterior extremity,
indicating three component segments and a large terminal section.
Pleural lobes very narrow, only the two anterior retaining any
semblance to anchylosed segments of the thorax; extremities of
extremities, prominently elevated, acutely tapering posteriorly;
segments attenuated and spinose, the spines drooping posteriorly and
approximately parallel; second spine from the thorax the longest
of all, the third nearly in line with it; four shorter subequal spines
included between these two pairs.

Surface——External surface smooth under low magnification but
minutely roughened by very fine, irregular anastomosing ridges
when examined with a strong lens.

Dimensions.—Length of glabella, 3.5 mm. Breadth of glabella in
front, 2.7mm. Breadth of glabella at base, 1.5 mm.

Type locality.—(610) Middle Cambrian: Chetang formation;
Chetang Cliffs, 7 miles (11.2 km.) north-northeast of Robson Peak.

Observations.—This species recalls at once Zacanthoides idaho-
ensis. It is closely allied to it but differs in its narrower antero-
lateral limb of the fixed cheek, shorter palpebral lobe, and apparent
absence of the frontal limb. The associated pygidium differs in the
size and arrangement of the spines of the flattened border.

Formation and locality —Middle Cambrian: (610) Chetang for-
mation ; gray shaly limestones in massive beds ; on northeast slope of
Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.)
north-northeast in direct line from summit of Robson Peak, north-
west of Yellowhead Pass, western Alberta, Canada.

ZACANTHOIDES ? CIMON, new species

Plate 7, figs. 6, 6a

Species known only from imperfect cranidia and fragments of a
pygidium.

Cephalon.—Cranidium rather small. Glabella very long relatively,
more than nine-tenths the length of the cranidium, but not quite twice
as broad as its length, broadly and quite prominently elevated medi-
ally, very feebly constricted laterally but expanding anteriorly, both in

42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the direction of the axis and at right angles to it; glabellar furrows

_rather broad and shallow, cutting up the glabella into obscure annula-

tions which are perceptible even upon the crest of the glabella ; occipi-
tal furrow moderately broad, uniform in depth between the dorsal
furrow ; occipital ring rather low, broad, expanded medially and pos-
sibly nodose. Fixed cheeks exclusive of the postero-lateral lobe
appearing as semielliptical extensions on either side of the medial
posterior portion of the glabella; greatest width of the fixed cheek,
exclusive of the postero-lateral lobe which has not been preserved,
rarely more than half the width of the medial portion of the glabella.
Palpebral lobe and ridge not differentiated, the two together forming
a cordate, strongly arcuate ridge with one extremity near the occipital
ring, the other directly in front of the anterior glabellar furrows, the
ridge cut off from the fixed cheek by a clearly defined groove ; medial
portion of the palpebral arc nearly in line with the posterior glabellar
furrows. Frontal limb obliterated medially. Frontal border very
narrow, upturned, probably somewhat thickened. Facial sutures
imperfectly preserved, the anterior section apparently . diverging
rapidly from the anterior extremity of the palpebral arc. Free cheeks
not preserved.

Pygidium—Pygidium known only from a couple of proximate,
parallel, caudal spines attached to the peripheral rim and connected
with a fragment of the axial lobe.

Surface —External surface microscopically shagreened.

Dimensions.—Length of cranidium, 6.2 mm. Length of glabella,
5.7mm. Width of medial portion of glabella, 3.2 mm.

Type locality —(63b) Ptarmigan Peak, Alberta, Canada.

Observations.—The two caudal spines which have been preserved
were probably about 10 mm. long before the loss of their tips. They
are exactly parallel to one another and separated by a space no greater
than the width of one of the slender spines.

The cranidium and the fragment of the associated pygidium both
suggest Zacanthoides, but as the cranidium might possibly belong to
a species of Albertella the generic reference is tentative. I do not
know of a similar described form of cranidium or pygidium.

Formation and locality—Middle Cambrian: (63b) Ptarmigan
formation; bluish-black, more or less finely arenaceous limestone in
layers 0.5 to 8 inches thick that form massive layers 450 feet (138 m.)
thick beneath the great Cathedral limestone ; east base of Ptarmigan
Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise
station on the Canadian Pacific Railway, Alberta, Canada.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 43

_ZACANTHOIDES CNOPUS, new species
Plate 6, figs. Io, Toa

Species known only from an imperfect cephalon and a portion of
the thorax.

Dorsal shield.—Dorsal shield rather small for the group, elongate-
oval in outline. Axial lobe convex, strong, as wide as the pleura
exclusive of the spinose extremities and elevated high above them
even in the shale.

Cephalon.—Cephalon apparently a little less than one-third of the
length of the dorsal shield, and about twice as broad as it is long.
Cranidium exclusive of the postero-lateral lobes somewhat pitcher-
shaped, broadly convex medially and posteriorly, flaring anteriorly.
Glabella rather low but relatively long, expanding slightly anteriorly
both with the axis and at right angles to it, broadly and very feebly
constricted medially ; dorsal furrows not very deeply impressed and,
between the posterior glabellar furrows and the occipital ring, almost
obsolete; anterior furrow also shallow, broadly arcuate; glabellar
furrows quite pronounced; posterior pair oblique, quite deeply
gouged toward the dorsal furrows but obsolete upon the subangular
crest of the glabella; medial pair similar in general character to the
posterior but shorter and less oblique; anterior pair reduced to very
obscure, lateral depressions at some little distance behind the anterior
extremity ; occipital furrow deeply incised distally but broad and
shallow upon the summit of the glabella; occipital ring low and
broad, expanded medially and bearing near the posterior margin
traces of an occipital node. Fixed cheeks narrow, the distance from
the palpebral lobe to the dorsal furrow less than half the width of
the glabella, auriculate in outline, exclusive of the postero-lateral
lobe ; postero-lateral lobe not preserved but doubtless very slender,
and probably petaloid. Palpebral lobe and palpebral ridge not
differentiated, the two together forming a cordate, sickle-shaped
ridge with one extremity near the occipital ring, the other directly
in front of the anterior glabellar furrows but at some little distance
behind the anterior extremity of the glabella; palpebral lobe and
ridge cut off from the cheek by a narrow deeply incised groove.
Frontal limb narrow, flattened, but little wider than the cordate
frontal border. Free cheeks wide and probably rather low, periph-
eral bofder abruptly constricted and produced posteriorly into very
slender, acutely tapering spines which apparently terminate opposite
the fourth thoracic segment.

44 SMITHSONIAN MISCELLANEQUS COLLECTIONS VOL. 67

Thorax.—Thoracic segments eight or nine in number, probably
nine. Axial lobe very coarse, wider than the pleural lobes and
strongly convex; annulations sharply defined and bearing a medial
node, probably indicating the former presence of a medial spine; the
slender spine upon the seventh thoracic segment still preserved, prob-
ably about 10 mm. long, or more than half the length of the dorsal
shield. Pleural segments, exclusive of the attenuated spinose ex-
tremities, very short; pleural furrows broad, almost as wide as the
including segment and moderately deep; extremity of first thoracic
segment apparently not spinose; extremity of second thoracic seg-
ment attenuated, posteriorly inclined and produced into a slender
spine a little longer than the unflexed portion of the segments;
extremities of the medial and posterior thoracic segments between
two and three times the length of the rest of the segment, strongly
inclined posteriorly.

Pygidium.—Pygidium not very well preserved, short. Axial lobe
relatively large and strong, obtusely truncate posteriorly; caudal
annulations almost as prominent as those of the thorax, four in
number with a terminal section. Pleural lobes of the pygidium not
preserved except the spinose extensions of the pleura which extend
backward approximately parallel to the axis of the shield, and almost
twice the length of the axial lobe.

Surface.—Character of external surface not preserved ; surface of
spines covered with a microscopically fine lacy venation.

Dimensions—Length of dorsal shield, 13.5+ mm. Length of
cephalon, 4.0+ mm. Greatest width of thorax, including the spinose
extremities, 11.0+ mm. Greatest width of thorax, excluding the
spinose extremities, 6.0 mm.

Type locality—(4v) Gordon Creek, Montana.

Observations.—The cranidium of this species is much like that of
Z. idahoensis, but the thorax has the great median spine on the
eighth segment instead of the fifth and the spinose extensions of this
pleura are relatively longer. The imperfection of the specimens
prevents closer comparison. Zacanthoides cnopus differs from
Z. typicalis and Z, spinosus very much as Z. idahoensis differs from
them.’

Formation and locality—Middle Cambrian: Gordon shale; (4v)
about 200 feet (61 m.) above the unconformable base of the Cam-
brian and 75 feet (22.9 m.) above the top of the quartzitic sandstones,

*Smithsonian Misc. Coll., Vol. 53, 1908, pl. 3, figs. 1-11.
* Tdem, p. 20.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 45

Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River,
Ovando quadrangle (U.S. G. S.), Powell County Montana.

NEOLENUS CONSTANS, new species
Plate 6, figs. 7, 7a

Species known only from a single caudal shield.

Pygidium.—Pygidium large and coarse, roughly semielliptical in
outline, about four-fifths as long as it is broad ; component segments
five in number including the terminal section. Axial lobe elongate-
conic in outline, almost as broad anteriorly as one of the pleural
lobes, evenly tapering toward the sharply rounded posterior ex-
tremity of the lobe; annulations distinct, becoming less prominent
and more closely spaced posteriorly. Lateral lobes strongly convex ;
segments feebly anchylosed especially toward the thorax; pleural
furrows broad and, toward the posterior extremity, obscure, arcuate
anteriorly, approximating more and more closely to the axis of the
shield posteriorly ; outer extremities of segments discrete and falcate
or even semispinose. Peripheral rim not very sharply defined, out-
lined by the flattening of the shield and by a series of shallow pits
which mark the terminations of the pleural furrows; outer margin
serrated by four broad-based, rather short spines quite sharply con-
cave opposite the extremity of the axial lobe.

Surface —External surface finely punctate, having the appearance
under high magnification of having been very finely etched with acid.

Dimensions.—Length of caudal shield, 20+ mm. Greatest breadth
of caudal shield, 25.0+ mm.

Type locality—(63b) Ptarmigan Peak, Alberta, Canada.

Observations —Although the extremity of the axial lobe is sharply
defined, there is a very obscurely elevated cuneate area extending
backward from the extremity and wedging out at the margin.

I do not usually like to found a species on a pygidium, but this
form is so distinct and strong that it seems worthy of such recogni-
tion. It differs from the pygidium of Neolenus serratus in having
one less pair of border spines, one less pleural segment indicated on
the pleural lobes, and a relatively shorter, broader axial lobe.

Formation and locality——Middle Cambrian: (63b) Ptarmigan
formation ; bluish-black, more or less finely arenaceous limestone in
layers 0.5 to 8 inches thick that form massive layers 450 feet (138 m.)
thick beneath the great Cathedral limestone ; east base of Ptarmigan
Peak 5.5 miles (8.8 km.) in an air line northeast of Lake Louise
Station on the Canadian Pacific Railway, Alberta, Canada.

46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

BATHYURISCUS ROSSENSIS, new species
Plate 5, figs. 5, 5a-d
Bathyuriscus (Poliella) sp. undt. Watcort, 1916, Smithsonian Misc. Coll.,
Vol. 64, No. 5, p. 355, pl. 46, fig. 7. (Described and illustrated.)

Dorsal shield—Dorsal shield a very smooth elongated oval, the
greatest breadth in the type less than two-thirds of the length. Axial
lobe well differentiated, moderately convex ;. pleura flattened in the
shale but retaining traces of rather a strong downward flexure at
the genal angle.

Cephalon.—Cephalon, exclusive of the genal spines, about two-
fifths as long as the entire dorsal shield, strongly contoured even in
the shale. Glabella quite low, almost as long as the cephalon, strictly
clavate in outline; dorsal furrows distinct, deepening anteriorly ;
anterior extremity expanded and broadly arcuate; posterior lateral
furrows rather broad and deeply intrenched, directed backward at
an angle of approximately 45° but evanescing abruptly before reach-
ing the medial line; other lateral furrows obsolete ; occipital ring
distinct, trigonal ; occipital furrow deeply gouged toward the distal
extremities but shallow and rather ill defined upon the crest of the
glabella ; occipital ring posteriorly produced and sharply angulated,
and bearing a short acute spine at the apex of the angle. Fixed
cheeks lower than the glabella, rather wide relatively, the distance
from the palpebral lobe across to the dorsal furrow a little more than
half the width of the medial portion of the glabella; postero-lateral
lobes very narrow and petaloid ; groove behind the posterior margin
very broad, especially toward the outer extremity. Palpebral lobe
narrow, strongly crescentic, about one-third as long as the glabella,
set so far back that the posterior extremity of the lobe is almost in
line with the occipital furrow. Palpebral ridge often rather obscure,
arching obliquely across from the anterior extremity of the palpebral
lobe and intercepting the dorsal furrow about half-way between the
outer extremity of the posterior lateral furrow and the anterior
extremity of the glabella. Facial sutures conspicuously sinuous, fol-
lowing along the low arch of the postero-lateral lobes of the fixed
cheeks, around the strongly convex palpebral lobe and the shorter
but almost equally convex anterior lobe; arc included between the
extremities of the facial sutures approximately one-third the peri-
phery of the cephalon exclusive of the genal spines.

Free cheeks of about the same width as the fixed cheeks, but more
plump, bearing short and rather broad infragenal spines and very
long, slender acute, scimiter-like genal spines which lie close to the

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 47

outer extremities of the thoracic segments and are produced back-
ward at least as far as the pygidium. Frontal border very narrow
anteriorly, widening slightly laterally.

Thorax.—Thoracic segments moderately wide, eight in number.
Axial lobe not quite so wide as the pleura and arched well above
them ; distal extremities of the axial segments produced into falcate
extremities about one-third as long as the pleural segments which
they overlie; medial portion of the axial segment probably elevated
into an obtuse node. Pleural segments doubtless rather strongly
flexed at their falcate outer extremities ; pleural furrows broad and
quite deep, much more steeply channeled along the anterior margin
than along the posterior, gradually disappearing distally ; outer ex-
tremities of the pleura acute and posteriorly directed, rounded aw ay
along the underlapping anterior margin.

Pygidium.—Pygidium quite large, contained between three and
four times in the length of the shield, sharply differentiated from the
thorax ; axial lobe of the pygidium subcylindrical, relatively slender,
abruptly evanescing at some little distance in front of the posterior
extremities ; included segments probably five in number, annulations
obsolete posteriorly but strongly defined anteriorly, that in front
and often the next behind it bearing an acute spine. Lateral furrows
broad and rather ill defined, approximately parallel, and inclined at
an angle of about 45° to the axis of the shield. Anterior segment of
the fused portion of the pygidium produced into a rather short,
posteriorly directed spine. Periphery of pygidium indented at the
caudal spine, squarely truncate or broadly constricted posteriorly.

Surface ——There is very little trace of an external sculpture except-
ing upon the genal spines which are longitudinally striated with very
fine anastomosing groovings. One cranidium, however, is sha-
greened with rather a coarse granulation and on this same individual
there are traces of three pairs of short, horizontal glabellar furrows
in front of the oblique posterior pair.

Dimensions —Length, 49.5 mm. Maximum width, 35.0 mm.
Length of cranidium, 21.0mm. Length of pygidium, 13.0 mm.

Type locality—(63}) Ptarmigan formation, Albertella shale zone ;
above Ross Lake, British Columbia, Canada.

Observations.—B. rossensis Walcott is, perhaps, best characterized
by the very much produced genal spines. They certainly extend as
far back as the pygidium and their attenuated extremities may
persist even to the posterior margin of the shield. There is a strong
tendency in this species toward the development of spines and nodes.

48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

There are infragenal as well as genal spines developed, and the occi-
pital ring and the axial ring both of the thorax and the pygidium
are nodulated. The triangular axial extensions in the pleural grooves
so characteristic of the genus are unusually well developed in this
species. The glabella is broad relatively, and only the posterior
lateral furrows are perceptible on the majority of the individuals.
The caudal shield is moderately large but less strongly annulated and
furrowed than in the majority of Bathyuriscus. The number of
thoracic segments is the same in the half-dozen individuals in which
the complete shields have been preserved.

The pygidium of B. adeus’* has a somewhat similar marginal spine
on each side, but otherwise the pygidia differ in many details. The
cranidium of B. belesis* is very similar but the associated pygidia are
quite dissimilar.

The pygidium described and illustrated as Bathyuriscus (Poliella)
sp. undt. I ° is now referred to this species. The two specimens then
known of were broken along the outer border and did not show the
spine on each side. By error the locality of the specimens was given
as 35e. They came from 35c as defined below.

In the collection made by Dr. Frank D. Adams and Mr. W. J.
Dick, 4 miles (6.4 km.) north of North Kootenay Pass, Alberta,
there are specimens of large species of Bathyuriscus that are appar-
ently identical with B. rossensis. They occur on the surface of very
thin layers of bluish-gray limestone in association with a typical
Albertella fauna as follows:

Agraulos stator Walcott
Vanuxemella nortia Walcott

Albertella bosworthi Walcott
Asaphiscus rossensis Walcott

Formation and locality—Middle Cambrian: (63j) Ross Lake
shale member of the Ptarmigan formation ; outlet of cirque above and
south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.)
south-southwest of Stephen on Canadian Pacific Railway; (63m)
Albertella zone; south slope of Mount Bosworth, about 500 feet
(152.4 m.) above the Canadian Pacific Railway track, 1 mile (1.6 km.)
east of Hector and 1.25 miles (2 km.) west of Stephen on Conti-
nental Divide; and (35c) also Albertella zone; drift blocks of silice-

* Smithsonian Misc. Coll., Vol. 64, 1916, pl. 47, figs. 3, 3b.
? Idem, p. 338, pl. 50, figs. 1, 1D.
*Idem, p. 355, pl. 46, fig. 7.

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 49

ous shale from the Ptarmigan formation, found on the south slope
of Mount Bosworth about 500 feet (152.4 m.) northwest of the
Canadian Pacific Railway track between Stephen and Hector, all in
British Columbia, Canada.

Also 4 miles (6.4 km.) north ef North Kootenay Pass, Alberta,
Canada. Specimens in Museum of McGill University, Montreal.

BATHYURISCUS cf. ROSSENSIS, new species
Plate 5, figs. 6, 6a

Cephalon.—Cranidium large and strongly contoured. Glabella
long and relatively narrow, somewhat clavate in outline, slightly
expanded anteriorly both along the transverse and the longitudinal
axis, the maximum elevation falling in front of the transverse median
line; glabellar furrows obscure in the majority of individuals, the
posterior pair rather broad and very strongly oblique, the pair in
front of them approximately horizontal or feebly inclined posteriorly,
the two anterior pairs very slightly inclined anteriorly ; occipital fur-
row broad but not very deep, persisting across the crest of the
glabella; occipital ring rather wide, cuneate, the posterior margin
produced, acutely ridged and angulated and bearing an obtuse spine
at the apex of the angle; dorsal furrows moderately impressed,
broad and feebly constricted medially, in the majority of individuals
more strongly divergent anteriorly than posteriorly; anterior ex-
tremity of the glabella broadly arched. Fixed cheeks low, rather
broad relatively, the distance from the palpebral lobe across to the
dorsal margin approximately half the width of the medial portion
of the glabella; postero-lateral lobe narrow but produced laterally ;
posterior furrow broad, oblique, its anterior margin in line with
the oblique posterior margin of the occipital ring; palpebral lobe
moderately wide, reniform, about three times the length of the
glabella, the median transverse line of the lobe falling a little behind
the median transverse line of the glabella; palpebral ridge obscure
in the majority of individuals, arching across from the palpebral
lobe and intercepting the dorsal furrows at or a little in front of the
next to the anterior pair of lateral furrows. Facial sutures outlined
as in figure, the anterior limb broadly arched. Character of free
cheeks not known.

Surface—Smooth or slightly roughened by obscure granulation.

Dimensions.—Length of cranidium, 30.0mm. Length of glabella,
28.5 mm.

* Smithsonian Misc. Coll., Vol. 53, No. 5, 1908, p. 214.

50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Type locality—(63m’) Mount Bosworth, British Columbia,
Canada.

Observations.—This form is known only from cranidia and pygidia
occurring in thin limestone lentiles in the shale with B. ros-
sensis. The glabella is longer and more slender proportionally than
that of rossensis. These differences are apparently too great to be
due to individual variation, or to compression and distortion. The
glabelle of Bathyuriscus sp. are strongly convex and on some speci-
mens the median ridge is strongly defined, especially toward the
anterior portion.

The associated pygidia are closely related if not identical with
those of B. rossensis except that the limestone form is narrower and
more elongate proportionally.

Formation and locality—Middle Cambrian: (63m’) Ptarmigan
formation (Ross Lake shale) ; thin lentiles of limestone included in
the shale ; south slope of Mount Bosworth, about 500 feet (152.4 m.)
above the Canadian Pacific Railway track, 1 mile (1.6 km.) east of
Hector and 1.25 miles (2 km.) west of Stephen on Continental
Divide, British Columbia, Canada.

BATHYURISCUS (POLIELLA) CHILO, new species
Plate) 5, fe. 4

Dorsal shield —Dorsal shield rather small, quite slender, elongate- —
oval in outline, the greatest width, exclusive of the free cheeks which
have not been preserved, a little more than half the length. Axial
lobe relatively broad in all three divisions of the shield and con-
spicuously elevated above the flattened pleura.

Cephalon.—Cephalon more than one-third the length of the dorsal
shield. Glabella large relatively, rather tumid, subrectangular in
outline, expanding very slightly near the front ; dorsal furrows feebly
impressed, rudely parallel excepting near the anterior extremity
where they tend to diverge ; front of glabella ill defined, very broadly

and very feebly arcuate; glabellar furrows obscure, the posterior

pair oblique, the medial and anterior pairs more nearly transverse ;
occipital furrow shallow; occipital ring imperfectly preserved, ap-
parently rather wide and similar in character to the anterior segments
of the thorax. Fixed cheeks imperfectly known, apparently rather
wide and broadly convex, the distance from the palpebral lobe to the
dorsal furrow more than half the width of the medial portion of the
elabella ; postero-lateral lobe narrow, short, obtusely petaloid at its
extremity ; posterior groove not very deep, in line with the occipital

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 51

ring; margin behind the groove increasingly wide away from the
axis. Palpebral lobe conspicuously elevated and not differentiated
from the palpebral ridge which cuts obliquely across the fixed cheek
and intercepts the dorsal furrows near the origin of the posterior
-glabellar furrows; raised margin of the lobe probably cut off from
the surface of the cheek by a broad and rather deep furrow. Other
characters of the cephalon not preserved.

Thorax.—Thoracic segments nine in number. Axial lobe strongly
convex, broader than the pleural lobes. Pleura short, the anterior
medial segments the most produced ; pleural furrows rather shallow,
almost as wide as the including segment ; extremities of the anterior
and medial segments apparently obtuse ; last three segments in front
of the caudal shield acutely falcate distally.

Pygidium.—Pygidium short, rudely lenticular in outline. Axial
lobe, strongly convex, relatively broad, subcylindrical, tapering
slightly toward the broadly rounded posterior extremity ; annulations
distinct but not conspicuous, indicating two component segments and
a terminal section. Pleural lobes somewhat flexuous, of approxi-
mately the same width as the axial; pleural grooving very obscure,
rudely parallel to the anterior margin. Peripheral rim narrow,
smooth, flattened, broadly arcuate.

Surface —External surface microscopically shagreened.

Dimensions.—Length of dorsal shield, 12.5+ mm. Greatest width
of dorsal shield, exclusive of the fixed cheek, 7.+ mm.

Type locality—(63n) Ptarmigan formation; Wonder Pass, west
of Gog Lake, British Columbia, Canada.

Observations —When in the field I referred this species to B. (P.)
sylla* of the Chetang formation, but comparison with the type
specimen of the latter showed that they differed in the nearly straight
sides of the glabella and narrower and shorter associated pygidium.
The most ‘nearly related species appear to be B. (P.) primus and
B. (P.) anteros* from which it differs in many details.

Formation and locality—Middle Cambrian: (63n) Ptarmigan ?
formation; bluish thin-bedded limestone northwest side of Wonder
Pass at east base of ridge west of Gog Lake, on Continental Divide,
in British Columbia, 19 miles (30.4 km.) southwest of Banff, Canada.

1 Smithsonian Misc. Coll., Vol. 64, 1916, p. 354, pl. 48, figs. 3, 3a-e.
* Idem, pl. 46, figs. 5, 6, 6a-c.

52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 4

Tholsastercila ? Jrindet. Walcott. ov. .). «ce. sous oss oslo oe ee eee 25
Fic. 1. (X2.) <A six-rayed spicule showing a central nodule. U. S.
National Museum, Catalogue No. 63711. (63i.)
1a. (X6.) Central portion of the disk of fig. 1 enlarged to show
structure.

Bocystites’? sp*undt. 2.2. cde ete: os aoe oe ee Eee 25
Fic. 2. (Natural size.) The only specimen known to me of this form.
U. S. National Museum, Catalogue No. 63712.

The specimens represented by figs. I, Ia, and 2 are from
(Locality 63j) Middle Cambrian: Ptarmigan formation (Ross Lake
shale) ; above Ross Lake, British Columbia.

Micromstra (Patertma) wapta Walcott. .......0. 3s. ok eee oe 25
Fic. 3. (X2.) Exterior of ventral valve. The type specimen (U. S.
National Museum, Catalogue No. 51402a). The figure 3 is
copied from Walcott, Smithsonian Misc. Coll., Vol. 53,
1908, pl. 7, fig. 6. Also Monogr. 51, U. S. Geol. Surv., 1912,
text fig. No. 29A, p. 357.

The specimen represented is from (Locality 35c) Middle Cam-
brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth,
British Columbia.

Obolus. paruus Walcott Ho2c5 fn ne ee ee ee 25
Fic. 4. (X 4.) Exterior of a ventral valve, the type specimen (U. S.
National Museum, Catalogue No. 51400a).
4a. (X4.) Exterior of a dorsal valve. U. S. National Museum,
Catalogue No. 51400b.

The specimens represented by figs. 4 and 4a are copied from Wal-
cott, Smithsonian Misc. Coll., Vol. 53, 1908, pl. 7, figs. 10, toa. Also
Monogr. 51, U. S. Geol. Surv., 1912, text figs. 37A and 37B, p. 408.

The specimens represented are from (Locality 35c) Middle Cam-
brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth,
British Columbia.

Acrothele collenst Walcott \. 5 :oica% since Sols daciecichls melee eis ae ves
Fic. 5. (X4.) A large ventral valve. U.S. National Museum, Cata-

logue No. 51410c.

5a. (X4.) Broken ventral valve showing false area. U. S.
National Museum, Catalogue No. 51410b.

5b. (X4.) Cast of a ventral valve showing the incurving of the
growth lines across the false area. U.S. National Museum,
Catalogue No. 514104.

5c. (X4.) Exterior of a dorsal valve. U. S. National Museum,
Catalogue No. 51410e.

The figures 5, 5a-c are copied from Walcott, Monogr. 51, U. S.
Geol. Surv., 1912, text figs. 55, B, C, D, and E, p. 641.

The specimens represented are from (Locality 35c) Middle Cam-
brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth,
British Columbia.

sd, sd’. (X 4.) Top and back views of the posterior portion of a
ventral valve. U. S. National Museum, Catalogue
No. 519730.

Se. (X4.) Side view of the type specimen, a ventral valve. U.S.
National Museum, Catalogue No. 51973a.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 2, PL. 4

SPONGE, CYSTID, AND BRACHIOPODS

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA

Acrothele colleni Walcott—Continued. PAGE

sf. (X 2.5.) Exterior of a dorsal valve with the cardinal slopes
rounded in by pressure. An imperfect valve beside it has
the outline of figure 5c. U. S. National Museum, Cata-
logue No. 51973c.

The figures 5d, 5e, and 5f are copied from Walcott, Monogr. 51,
U. S. Geol. Surv., 1912, pl. 63, figs. 6, 6a, 6b.

The specimens represented are from (Locality 4q) Middle Cam-
brian: Gordon shale near Gordon Mountain, Ovando quadrangle
(US: G: S.), Montana.

Dera emnies. Walcott’. 7 . Se 2a Aion aiid ea oa cies eels eo bee
Fics. 6, 6a. (Natural size.) Ventral valves of varying outline owing
to distortion in the shaie. U.S. National Museum, Cata-
logue Nos. 52277a and 52277).
6b. (Natural size.) Cast of interior of a ventral valve. U. S.
National Museum, Catalogue No. 52277d.
6c. (X2.) Ventral and dorsal valves compressed and resting
against each other at the posterior margins. U.S. National
Museum, Catalogue No. 52278b.

The figures 6, 6a-c are from Walcott, Monogr. 51, U. S. Geol.
Surv., 1912, pl. 80, figs. 2a, 2b, 2c, 2e.

The specimens represented are from (Locality 4w) Middle Cam-
brian: Gordon shale on Youngs Creek, Ovando quadrangle
(U. S. G. S.), Montana.

7, 7a. (X2.) Ventral valves of varying outline owing to dis-
tortion in the shale. U. S. National Museum, Catalogue
Nos. 63713 and 63714. (63j.)
7b. (X2.) Cast of interior of a dorsal valve. U. S. National
Museum, Catalogue No. 63715. (63i.)
7c. (X3.) Interior of a compressed dorsal valve. U.S. National
Museum, Catalogue No. 51407. This figure is from Wal-
cott, Monogr. 51, U. S. Geol. Surv., 1912, text fig. No. 64,
p. 748.
The specimen represented by 7c is from (Locality 35c) Middle
Cambrian: Ptarmigan formation (Ross Lake shale): Mount Bos-
worth, British Columbia.

8. (X2.) Cast of two ventral valves in limestone. U. S.
National Museum, Catalogue No. 63716. (63m.)

8a. (X 3.) Exterior of a ventral valve. U.S. National Museum,
Catalogue No. 63717. (63m.)

8b. (X3.) Area of a ventral valve. U. S. National Museum,
Catalogue No. 63718. (63m.)

8c. (X2.) Exterior of a dorsal valve. U. S. National Museum,
Catalogue No. 63719. (63m.)

The specimens represented by figs. 7, 7a-b are from siliceous shale
(Locality 63j), Middle Cambrian: Ptarmigan formation (Ross
Lake shale) ; above Ross Lake; and figs. 8, 8a-c from limestone
interbedded in the shale of locality 63m, Middle Cambrian: Ptarmi-
gan formation; Mount Bosworth, both in British Columbia.

NESTE SACERCHMICELU CAGE Ge NV AL COLE. <1 chard oeetmetetere o e IOE r re ot arin Sk ota soe Sielele otiee sts
Fic. 9. (X 3.) Imperfect exterior of a small ventral valve. U. S.
National Museum, Catalogue No. 63720.

The specimen represented by fig. 9 is from _ limestone
(Locality 61.0), Middle Cambrian: Chetang formation; Robson
District, Alberta.

54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 5

AHyohthellus hectori, Walcott..a6 epic. . .coen coco ee ee eee oe eee
Fic. 1. (X8.) Section of a tube enlarged to show surface charaniaee
U. S. National Museum, Catalogue No. 63721.

The specimen represented is from (Locality 35c) Middle Cam-
brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth,
British Columbia.

yivolthellus flagellum (Matthew) ........055-0 500 ce e0c cesses eee
Fic. 2. (X 3.) A long curved tube. U. S. National Museum, Cata-
logue No. 63722. The figure 2 is the same as fig. 8, pl. 1,

Walcott, Canadian Alpine Journ., Vol. 1, 1908.

From (Locality 14s) Middle Cambrian: Stephen formation;
Mount Stephen, British Columbia.

2a. (X4.) A group of four small tubes attached to a valve of
Wimanella simplex. U. S. National Museum, Catalogue
No. 63723.

From (Locality 63)) Middle Cambrian: Ptarmigan formation
(Ross Lake shale) ; above Ross Lake, British Columbia.

Hyoltthes cecrops Walcott). 0% oc. 0 viele ss an pa eee Oo aa eee
Fic. 3. (Natural size.) Dorsal view with shell broken away. The
type specimen. U. S. National Museum, Catalogue
No. 63724.
3a. (X4.) Ventral view of a small specimen that is only slightly
compressed. U.S. National Museum, Catalogue No. 63725.
3b. (Natural size.) Dorsal view of a small wide specimen flattened
in the shale. U.S. National Museum, Catalogue No. 63726.
3c. (X2.) Inner side of an operculum associated with the speci-
men illustrated by figs. 3, 3a-b. U. S. National Museum,
Catalogue No. 63727.
The specimens represented by figs. 3, 3a-c are from (Locality
631) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ;
above Ross Lake, British Columbia.

Bathyuriscus (Poltella) chilo. Walcott. ....: v.52. - one -e ee
Fic. 4. (X 3.) Small dorsal shield a little injured by weathering.
U. S. National Museum, Catalogue No. 63728.

From limestone (Locality 63n), Middle Cambrian: Ptarmigan
formation: Wonder Pass, British Columbia.

Bathyuriscus rossensis Walcott............... hace pet ae
Fic. 5. (X 1.5.) A nearly perfect cranidium. U.S. National Museum,
Catalogue No. 63720.
sa. (Natural size.) Interior of a large free cheek. U.S. National
Museum, Catalogue No. 63730.
5b. (X2.) A pygidium somewhat crushed in the shale. U. S.
National Museum, Catalogue No. 63731.

PL. 5

67, NU. 2,

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

ie dln ee

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PLT AE OES FBR AE OEE bi

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, AND TRILOBITES

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NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA

Bathyuriscus ressensis Walcott—Continued. PAGE

5c. (X2.) Asmall, fairly well-preserved pygidium. U.S. National
Museum, Catalogue No. 63732.

sd. (Natural size.) A crushed dorsal shield, illustrating the general
characters of the species. U. S. National Museum, Cata-
logue No. 63733.

The specimens represented by figs. 5, 5a-d are from (Locality
631i) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ;
above Ross Lake, British Columbia.

aryNItSeWS Cl: FOSSeNStS WAlGOtBiacavtagcenshe cece nscseav vet aees es cees
- Fic. 6. (Natural size.) A large, partially exfoliated cranidium. U. S.
National Museum, Catalogue No. 63734.
6’. Side outline of fig. 6.
6a. (X 3.) Pygidium associated with the cranidium represented by
fig. 6. U. S. National Museum, Catalogue No. 63735.
6a’. Side outline of fig. 6a.

The specimens represented by figs. 6, 6a are from thin limestone
layers interbedded in the Ross Lake shale (Locality 63m’), Middle
Cambrian: Ptarmigan formation; Mount Bosworth, British
Columbia.

on
OV

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 07

DESCRIPTION OF PEATE 6

Ptychoparia~charaz, Walcott. .. 0 .niss oscrnes ieee abe sce eee 31
Fic. 1. (X2.) A cranidium, and the type specimen of the species.
U.S. National Museum, Catalogue No. 63736.

From locality 4v, Middle Cambrian: Gordon shale; Gordon
Creek, Montana.

Piycohoparta #2 ctlles Walcott... sccee te sh.s <6 hee eee Bn fy 32
Fic. 2. (X 5.) A small cranidium and the type specimen of the species.
U. S. National Museum, Catalogue No. 63737.

From limestone of locality 63d, Middle Cambrian: Ptarmigan
formation; Ptarmigan Mountain, Alberta.

Piychopatia’ candace Walcott. 1.0)... .0c0stseine Uae sae <b eee 28
Fic. 3. (X2.) A flattened dorsal shield with its pygidium broken
and pressed down and free cheeks detached. They are out-
lined from another cephalon which has one free cheek on
which there appears to be the base of a postero-lateral
spine. U.S. National Museum, Catalogue No. 63738.
3a. (X6.) Specimen of a dorsal shield with ten thoracic segments.
U. S. National Museum, Catalogue No. 63739.

From locality 4v, Middle Cambrian: Gordon shale; Gordon
Creek, Powell County, Montana.

Piychoparta: pylas Waleott. ox.0...0h..c05 00s ena siete ee eee 33
Fic. 4. (X6.) <A small dorsal shield. The palpebral lobes and some

details restored from other specimens. U. S. National
Museum, Catalogue No. 63740.

4a. (X4.) A badly crushed dorsal shield well illustrating thoracic
segments and parts of cranidium. U.S. National Museum,
Catalogue No. 63741.

4b. (X2.) A small cranidium flattened in the shale. U. S.
National Museum, Catalogue No. 63742.

4c. (X2.) The largest cranidium observed, illustrating the rapid
increase in size of the frontal limb with increase in size of
cranidium. U.S. National Museum, Catalogue No. 63743.

From locality 4q, Middle Cambrian: Gordon shale; on ridge
between Gordon and Youngs Creeks, Powell County, Montana.

Crepicephalus chares Walcctt. o./.ccccus once ose Sess eee ee eee 35
Fic. 5. (X 3.) Broken cranidium showing surface characters. U. S.

National Museum, Catalogue No. 63744.

5a. (X 3.) Free cheek associated with fig. 5. U. S. National
Museum, Catalogue No. 63745.

5b, 5c. (X3.) Pygidia associated with specimen represented by
fig. 5. U.S. National Museum, Catalogue Nos. 63746 and
63747.

From locality 63d, Middle Cambrian: Limestone of Ptarmigan
formation; Ptarmigan Peak, Alberta.

PL.

NO. 2,

VOL. 67,

SMITHSONIAN MISCELLANEOUS COLLECTIONS

CAMBRIAN TRILOBITES

NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA

ERNE See CPUL UPI VN IE GIUE 2 ceca crema nieiacio.s s'-)<.dclannie sc Slaleciics's sadain eee dees
Fic. 6. (Natural size.) A nearly perfect dorsal shield, the type speci-
men. U.S. National Museum, Catalogue No. 61729. After

Walcott, Smithsonian Misc. Coll., Vol. 64, pl. 36, fig. 6.

From locality 35c, Middle Cambrian: Ptarmigan formation
(Ross Lake shale) ; Mount Bosworth, British Columbia.

IMCOLEIUS A GONSLOMS EINVAL COLE: a. era xet era reaete ein eolioke SEES Iie oe 'ovevels'ova a's
Fics. 7, 7a. (Natural size.) Top and side views of the type specimen
of pygidium. U.S. National Museum, Catalogue No. 63748.

From locality 63b, Middle Cambrian: Limestone of Ptarmigan
formation; Ptarmigan Peak.

Picnopsrs chwumericanus Walcott: . 2.21 acbtiite deste edd esse eeee cess
Fics. 8, 8a, 8b. (X 1.5.) Broken cranidia that illustrate the form and
details of the cranidium. U. S. National Museum, Cata-

logue Nos. 63749, 63750, 63751.

From locality 63j, Middle Cambrian: Ptarmigan formation (Ross
Lake shale) ; above Ross Lake.

MrmCCNONIES. CAUFIIG NVALCOEE. . sc a coe Poe eee e Os ban date ede Sclecsoans
Fic. 9. (X 4.) The type specimen of the cranidium, which is preserved
in limestone and retains its original convexity. U. S.
National Museum, Catalogue No. 63752.
oa. (X4.) Pygidium associated with fig. 9. U. S. National
Museum, Catalogue No. 63753.

From locality 610, Middle Cambrian: Limestone of Chetang
formation; Robson Peak district, Alberta.

muLaminotacs cnopus WalcOlts...camisaatae Uitte <class cicdlv «eo islet odes ave
Fic. 10. (X 3.) <A broken dorsal shield illustrating thorax. U. S.
National Museum, Catalogue No. 63754.
toa. (X2.) A cranidium associated with fig. 10. U. S. National
Museum, Catalogue No. 63755.

From locality 4v, Middle Cambrian: Gordon shale; Gordon
Creek, Montana.

ios)
NI

58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 7

: PAGE

Alberiella. levis. Waleotti2.d ce cacesate esc as atone teeelaret hea Eee 39

Fic. 1. (X3.) The type specimen of cranidium. U. S. National
Museum, Catalogue No. 63757.
1a. (X4.) . Pygidium associated with fig. 1. U. S. National
Museum, Catalogue No. 63758.

From locality 61w, Middle Cambrian: Chetang formation lime-
stone; Terrace Creek, Robson district, Alberta.

Albertella boswortht Walcott... +2 «sansa cecal. -aee eee eee 38
Fic. 2. (X 4.) <A cranidium preserving its natural convexity. U. S.
National Museum, Catalogue No. 637509.
2a. (X3.) Asmall associated free cheek. U.S. National Museum,
Catalogue No. 63760.
2b. (X4.) An associated pygidium preserving its convexity and
narrow form. U.S. National Museum, Catalogue No. 63761.

From locality 6141p, Middle Cambrian: Chetang formation lime-
stone; Coleman Creek, Robson district, Alberta.

3, 3a. (X1.5.) Almost entire dorsal shields somewhat flattened
in the shale. U. S. National Museum, Catalogue Nos. 63762
and 63763.

The specimens represented are from (Locality 63)) Middle Cam-
brian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake,
British Columbia.

ab, 3c. (X 2.) Cranidium and pygidium for comparison with those
of Albertella helena. U.S. National Museum, Catalogue
Nos. 53413 and 53415. The figs. 3b, 3c are after Walcott,
Smithsonian Misc. Coll., Vol. 53, 1908, pl. 1, figs. 4 and 6.

The specimens represented by figs. 3b and 3c are from (Locality
35c) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ;
Mount Bosworth, British Columbia. ,

ad. (xX 12.) Matrix of a minute cranidium impressed on the sur-
face of a valve of Wimanella simplex. U. S. National
Museum, Catalogue No. 63764.

From locality 63i, associated with figs. 3, 3a.

Albertelia: helena. WaleGtt.. 6.0 <.s\.% since el'd canna Sheen eee 30
Fic. 4. (Natural size.) A nearly entire dorsal shield, the type speci-
men. U.S. National Museum, Catalogue No. 53410. The
fig. 4 is after Walcott, Smithsonian Misc. Coll., Vol. 53,
1908, pl. 2, fig. I.

The specimen represented by fig. 4 is from (Locality 54) Middle
Cambrian: Gordon shale; Scapegoat Mountain, Powell County,
Montana.

PL.

67, NO. 2,

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

CAMBRIAN TRILOBITES

NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 59

Albertella helena \Walcott—Continued. PAGE

5. (X2.) A dorsal shield with a more perfect cephalon than that
. on fig. 5a. A matrix of a fine pygidium occurs just below on
the same fragment of rock. U. S. National Museum,
Catalogue No. 63765.
5a. (X3.) A nearly entire dorsal shield. U.S. National Museum,
Catalogue No. 63766.

The specimens represented by figs. 5, 5a¢ are from the siliceous
shales of (Locality 63j) Middle Cambrian: Ptarmigan formation
(Ross Lake shale) ; above Ross Lake, British Columbia.

Peer OMseNie “CMMOI NV AICOLE. sitttee nee case < Ce edactaddcesdasctvceces

Fic. 6. (X 3.) Cranidium preserved in limestone. U. S. National
Museum, Catalogue No. 63767.

6a. (X 3.) Fragment of an associated pygidium. U. S. National
Museum, Catalogue No. 63768.

From locality 63b, Middle Cambrian: Ptarmigan formation;
Ptarmigan Peak, Alberta.

PEP ICHENNOTIGG WV AlCOtL<:cccicn carat dein wia visi: oan vvrelessereesacecsvedes
Fic. 7. (X2.) A nearly entire dorsal shield somewhat crushed in the
shale. The type specimen. U. S. National Museum, Cata-
logue No. 61728. After Walcott, Smithsonian Misc. Coll.,

Vol. 64, pl. 36, fig. 5.

The specimen represented is from locality 35c, Middle Cambrian:
Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British
Columbia.

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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 3

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

IV
No. 3.—FAUNA OF THE MOUNT WHYTE FORMATION

(WitTH PLatTEs 8 TO 13)

BY
CHARLES D. WALCOTT

(PUBLICATION 2480)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
SEPTEMBER 26, 1917

BALTIMORE, MD., U. S. A.

ab ae

CAMBRIAN GEOLOGY AND PALEONTOLOGY

IV
No. 3—FAUNA OF THE MOUNT WHYTE FORMATION

By CHARLES D. WALCOTT
(With PLatEs 8 To 13)

CONTENTS PAGE

LN ROGHIELLIGIN. le pik Gao Che 6 DIR GOSIEOIESIn sc c's 0 CRG ICICI OIC er aon Re Rcaec 61

SEA rap IC sPOSIbIOM OL ter TAMA... semiarid sce «(elise we oes ses coe es 62

ROHS SMO MEL INCRE ALINI Arye cers ete ocays.<ie.a'o'cisuttitremere entree ereinicil sat sieiele 6 cio.ce efe.arcs 65

MesciapMonrop peneta and SPECIES... .. geese cust ween se wees ceeds cecesios 67
ILLUSTRATIONS

PLATES FACING PAGE

S, (Gogie ail Ae NAO CMON PLR OES. cols Doe oI SEER Tec SOIR 104

OMCOM NE TLOGMUSHANG cIVESONUCES «.. stmt eltteides sie be else © oldie tees elec 106

10. Corynexochus, Micromitra, Acrothele, Wimanella, and Obolus...... 108

11. Crepicephalus, Ptychoparia, Olenopsis, Dorypyge, and Shafferia...... 110

12. JPW DONO 3 Sout s Oe USS DOC AEE 6 0 ce ULM D Et GDC CCRC Cn mae 112

pa erauias Olenopsts, and) Piycho part. ooo .c.c0-0 ss once cece vec eens II4
INTRODUCTION

The name Mount Whyte formation was proposed in 1908* for a
series of alternating bands of limestone and siliceous and calcareous
shale found on the north slope of Mount Whyte with a total thickness
of 386 feet (117.7 m.) ; on the south slope of Mount Bosworth 390
feet (118.9 m.) ; on the north slope of Mount Stephen above railroad
tunnel 315 feet (96 m.), and on the southeast slope of Castle Moun-
tain 248 feet (75.5 m.). The Mount Whyte and the Castle Mountain
sections are on the eastern slope of the Continental Divide in Alberta,
and the Mount Bosworth and Mount Stephen sections on the western
slope in British Columbia, Canada.

The included fauna was referred to as of Lower Cambrian age and
with it by inference a fauna of undetermined stratigraphic position,’
now known as the Albertella fauna of the Middle Cambrian.

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 4.
*For explanation of this reference see Smithsonian Misc. Coll., Vol. 67,
pp. 9-12.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 3
61

62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

In 1914 Mr. L. D. Burling concluded after a thorough and admir-
able study that on paleontological evidence the Albertella fauna was
of Middle Cambrian age and that the specimens of Olenellus found in
the Mount Whyte formation were examples of recurrence. On the
basis of this conclusion Burling placed the Mount Whyte formation
in the Middle Cambrian.

The discovery that the Albertella fauna occurs at an horizon 500
feet (152.4 m.) above the Mount Whyte formation materially affects
this conclusion.”

Several stratigraphic sections that include the Mount Whyte
formation have been published * and others will be after the conclu-
sion of field work in 1917. The presentation and discussion of all
sections studied will be given in a future paper on the stratigraphy of
the formation.

STRATIGRAPHIC POSITION OF THE FAUNA

All of the stratigraphic sections in their upper portion have varying
thicknesses of calcareo-arenaceous beds and bands of oolitic lime-
stone. Inthe upper layers of limestone there is usually a well-marked
fauna and at this horizon in three sections, at Mount Assiniboine,
Ptarmigan Peak, and Mount Stephen, the fauna includes a represen-
tation of the genus Crepicephalus, which attains its greatest develop-
ment in the Middle and Upper Cambrian of America, where 16
species or more are known, the greater proportion being in the Upper
Cambrian. The central portions of the sections include siliceous
shales and finely arenaceous beds and relatively few fossils, while the
beds toward the base are usually thin-bedded, more or less slightly
calcareous sandstones, and contain a characteristic Lower Cambrian
fauna with abundant fragments of ,.both Olenellus and Mesonacis,
and without traces of forms usually considered characteristic of the
Middle Cambrian fauna.

The fauna of the upper oolitic limestone in the Mount Stephen
section at locality 58k, about 5 feet (1.5 m.) below the top of the
Lower Cambrian in thin-bedded bluish-black and gray limestoné
(3 feet) forming 1 of Mount Whyte formation, and the interbedded
limestone at the top of 2, Mount Stephen section; just above the
tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of
Field, British Columbia, includes:

2 Canadian Geol. Surv., Museum Bull., No. 2, Geol. Ser., No. 17, 1914, p. 36.
2 Smithsonian Misc. Coll., Vol. 67, 1917, pp. 12-18. ;
®Idem, Vol. 53, 1908, pp. 212-215.

Canadian Alpine Journal, Vol. 1, No. 2, 1908, pp. 240-242.

Smithsonian Misc. Coll., Vol. 67, 1917, pp. 15, 16.
*Tdem, Vol. 64, 1916, pp. 203-204.

SNLOIS SS) FAUNA OF THE MOUNT WHYTE FORMATION 63

Acrotreta sagittalis taconica (Walcott)
Helcionella elongata Walcott

Scenella varians Walcott
Parmophorella sp.

Hyolithes billingsi Walcott
Ptychoparia clusia Walcott
Ptychoparia thia Walcott

Ptychoparia (pygidia)

Olenopsis agnesensis Walcott
Crepicephalus celer Walcott
Bathyuriscus (Poliella) primus Walcott

In the Ptarmigan Peak section the upper oolitic (acrece at locality
63a, east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line
northeast of Lake Louise station on the Canadian Pacific Railway,

Alberta, includes:
Nisusia (Jamesella) lowt Walcott

Wimanella catulus Walcott
Hyolithes billingst Walcott
Ptychoparia ? cercops Walcott
Crepicephalus cecinna Walcott

At the Gog Lake section, locality 62w, No. 1 of section; oolitic
limestone ; about 400 feet (123 m.) below summit of ridge above Gog
Lake below Wonder Pass on Continental Divide, in British Columbia,
19 miles (30.4 km.) southwest of Banff, Alberta, the fauna has sev-
eral species that occur at localities 58k, 63a above, and 61d (Foot-
note, p. 64), and includes:

Archeocyathus (A.) pneu Walcott
Kutorgina cf. cingulata Billings
Micromitra (Paterina) labradorica (Billings)
Nisusia (Jamesella) lowit Walcott
Acrotreta sagittalis taconica (Walcott)
Helcionella elongata Walcott

Scenella varians Walcott

Hyolithellus ? sp. undt.

Hyolithes billingsi Walcott
Crepicephalus cecinna Walcott
Ptychoparia cf. gogensis Walcott
Ptychoparia skapta Walcott
Ptychoparia thia Walcott

Olenopsis cleora Walcott

Dorypyge damia Walcott

The fauna listed from the three localities gives a general concep-

tion of the fauna associated with Crepicephalus in the upper portion.

of the formation. Its relations now appear to be more with the

1Tt must be recalled that all collections were obtained as incidental to
stratigraphic work and are necessarily a very imperfect representation of the
entire fauna at each locality and horizon; future thorough collections should
yield much additional data.

64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Mount Whyte than with the Ptarmigan fauna, but further field work
may change this view.”

The fauna of the central and lower portions of the formation is
given in the following table of genera and species:

Position in formation

Genera and species
Lower | Middle | Upper

Archeocyathus (A.) atreus Walcott.............000. Aes ae S<
G ORIG SrOMICa NW AlGOUE oem eens vs 3) RE
Micromitra (Paterina) charon Walcott..............
Micromitra (Paterina) labradorica (Billings)........
Micromitra (Iphidella) pannula (White)............
Kutorgina cf. cingulata Billings .......4.......0.0605
Obolus Gamo Walcott. .t0-. eos ovsur. » « ookae tae eens
Acrotreta sagittalis taconica (Walcott)..............
Acrothelenciiitis: Walcott: »c.).6n ens - eee eee
Nisusia (Jamesella) lowi Walcott............0.00000: ae
Nisusta festinata (Billings). oe. ce. ss los ende keen Sx
Wimanella icatulus Walcott. ©... ...../2oeieecss eee
Flelcionelanclongata! Walcott. 00... ...ss bebe FS
Hyotithes billings: Walcott 2...2. ..;.'. eek e lee x
Hyoltthes cf. corinatus Matthew ..............--0..-
Ei voleihesvso iat: o.2 soc eee ate ok ox s
Hyolithellus cf. micans Billings...............++ecaees
Fyolithellvs spa qindts acacstu ck. eonceee. neat
Pelaciella) spatingts (a). aed tee nds ee eee eee
Pelasiclla sincere cites cits.< = 36 oie sis od RR ee
PORMOPROVENG SD sin. Ac ok tee akc ee ae
wcenclla wartans Walcott). > cls c2 hs eee x
Shaiierta cruswai Waleotts...0a..oo28. 5 oe aa eee
Bradoria *(lareeispecies)).si. ute wasnt a eee
FLV MenOCarts SMe TMs os & «sia. < G dc E
Alutay (small species)... ce sc. «5 4 2h bee 0 eee at
Apraulos charaps NValeott.«..\.2..0is2.. sae. ones ><

PR ON rn os

iy es aa ty REED AE tte eer

Se ae
bt ete Gee

RAR A KK:

eX Eee

* Almost at the top of the oolitic limestone in the Mount Shaffer section at
locality 61d, southwest slope of Mount Shaffer on Canyon side, on trail to
Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station, on Canadian
Pacific Railroad, British Columbia, the fauna is Lower Cambrian in character
and includes:

Micromitra (Paterina) labradorica Shafferia cisina Walcott

( Billings ) Corynexochus senectus (Billings )
Micromitra (Iphidella) pannula (White) Agraulos ? unca Walcott
Acrotreta sagittalis taconica (Walcott) Zacanthoides
Nisusia (Jamesella) lowi Walcott Ptychoparia lux Walcott
Scenella varians Walcott Ptychoparia sp. undt.

Pelagiella sp. undt. (a) Mesonacis gilberti (Meek)

NOT 3 FAUNA OF THE MOUNT WHYTE FORMATION

Genera and species

Position in formation

Lower

Middle

Upper

Pieeuilosi Unco Walcott, v2. <2)... jee lewia tas ei! os o's
Olenopsis agnesensis Walcott. ....scncane oes sse0ee:
CEMON SES C1207 Walcott. asics. soo sta ages se sk a whens
DITERGESESHELETO, NWAICOU 6 oc vec sss ORs ea aly wets
Oilenopsis leuka Walcott .2...% 0... dadeesees oe een cee:
Piychoparia adina Walcott. ........ canes cewiets tele n's e
Pryehoparia coring Walcott. .:..... 2g net nastiness
Ptychoparia cf. carina Walcott..... <a RRR Sie
Piychoperia. 2 cercops. Walcott... cine. ssc se mse ss 5's
iPivchoparia 7 cleadas Walcott. ....tecencn cs vce ncss ss
iienoparia-cleow Walcott. 0.2... Seeawahiex oo 68 2 Ss
miychoparsa cihisva: Walcotte. .(..: s+ seeeneccienenae oss
cho pama cossts- Waleott...\...:./s tyamestsiee:s fois. e080
Piucheparia cuneds Walcott... << iguecaswis.« <cs0.0 08s
Ptychoparia cf. cuneas Walcott............eeeeee eee |
Pivenoparia gogensts Walcott. ..... dese ssc esc oases
Picnopurma ina WalcGth. sss... ibamein sets oe owe She ts
LUN GHOPOIVGN PICTOU NV AlCOLt ss os. cisateteyeleves aisles ete) stosee
ivchoparias pia. Walcotts ii... . ibe se ices} see.
ivehopariaeci. pra Walcott, . . ..sjasecs + dejo ee tee Dare
IRIN GHOpaiG wSkOptan NV alCOtt..\.% .jebtaeats sic ares «
Pijehoparia thia Walcott... .... Gass ne inna sees e's
Pivchoparia sp. undt.............28 ete ie re Aa sce
Grepicephalus cecinna Walcott. .i.c2ce. eevee ee ees
Grepisepnatisnceler NNialGott.: : «5 aectetimiceiciee elci=t= ose 0
Morvryce amma. Walcott 260s «sige pace see ee eos
Corynexochus senectus (Billings) ............6..0005
Corynexochus (Bonnia) fieldensis Walcott...........
iexonacts eulberis. (Meek) s. ccsie ees eees cies eee ss
Olenelius canadensis. Walcott. . «semen. ae - 2528s ee
Over aiagce sire tin dtie sacctrs « slcvs evs Skoterert Neel sare eee siete aie
Bathyuriscus (Poliella) primus Walcott..............
IBAA UDA ISICU RS AS Dee vi chinettaoies cadirastb oreo ha dO GH OO CeAD Ore

oe.

x XX

eK aa oe

Dae

SE ROD

UB Dr Soa

x
x
x

ee or

RO:

DK Oa OR DON TN OR a ee

NOTES ON THE FAUNA

One of the striking features of the 28 genera and 60 species of the
Mount Whyte fauna is the presence of several species common to it
and to the Lower Cambrian fauna of Newfoundland and the Cham-
plain Valley of Vermont. In order to make this clear I have
illustrated on plate 10, Corynexochus (Bonnia) parvulus (Billings )
from the Atlantic Province (figs. 1, Ia-c) and beside it C. (B.)

66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

fieldensis (Walcott) (figs. 2, 2a-c) from British Columbia ; and on
plate 9, Corynexochus senectus (Billings) from the Atlantic Province
(figs. 1, ta-d) and beside it specimens considered identical from
British Columbia (figs. 2, 2a-c). Mesonacis vermontana (Hall)
(fig. 3) from the Atlantic Province is the representative of Mesonacis
gilbertt (Meek) (fig. 4) from British Columbia. All of these species
have about the same range of individual variation both in the Atlantic
Province and British Columbia.”

Other species common to the Atlantic Province Lower Cambrian
fauna and the Mount Whyte fauna are Micromitra (Paterina)
labradorica (Billings), Kutorgina cf. cingulata (Billings), Acrotreta
sagittalis taconica (Walcott), and Nisusia festinata (Billings).

There are several species of Ptychoparia from Lower Cambrian
formations elsewhere that are very closely related to species from the
_ Mount Whyte formation. These are now illustrated on plates 11 and
12, for the Mount Whyte species, and on plates 14 and 15, for the
species of other formations. Ptychoparia cuneas and P. cossus
(pl. 11) may be compared with P. crates and P. crantos (pl: 15)
from Bic Harbor on the Lower St. Lawrence River, P. skapta (pl.
12, fig. 9) and P. deldon (pl. 15, fig. 2), P. thia (pl. 12, fig. 6) and P.
adamsi (pl. 14, fig. 8a). With larger collections the allied species
from the two sides of the continent would undoubtedly be much in-
creased in number.

The presence of such a strong connecting series of forms at such
widely separated localities and so far north on the continent indicates.
a northern origin of the later phases of the Lower Cambrian or
Olenellus fauna.

The trilobites, other than the Mesonacidz, indicate the rapid
approach of the large series of genera and species that mark the
Middle Cambrian fauna of North America. The Conocoryphide is
represented by forms that range throughout the Cambrian although
their range of variation may be sufficient to justify applying specific
names to the varieties from the Lower, Middle and Upper Cambrian.
Ptychoparia pia (pl. 12, fig. 8) is an illustration, also P. ? cleadas
(pl pro ios 2)

*Comparisons of the eastern and western forms of Corynexochus senectus
may be found in observations on the species made by me in 1916. Smithsonian
Misc. Coll., Vol. 64, 1016, pp. 321-322.

* Plates 14 and 15 will accompany a paper on certain Lower Cambrian genera
and species of trilobites which wil] be issued as Number 4 of this volume on
Cambrian Geology and Paleontology.

NOs 3 FAUNA OF THE MOUNT WHYTE FORMATION 67

The generic relations of the Mount Whyte fauna to the superjacent
Ptarmigan formation Albertella fauna is close despite the 500 feet
(152.4 m.) of barren strata between the two faunas. Of the 28
genera of the Mount Whyte fauna 13 are represented in the Alber-
tella fauna, and of the genera not present in the Albertella fauna
3 occur above it in the Stephen formation. More complete col-
lections will undoubtedly increase the number of genera common to
the two and at the same time may increase the number that are
restricted to the Mount Whyte fauna.

Acknowledgments—tThe drafts of the descriptions of species of
Ptychoparia for this and other papers to follow were drawn up by
Dr. Julia Gardner, who studied the material with great care.

The profiles used in illustration are by Miss Frances Wieser, and
where it was necessary to have the photographs retouched in order
to bring out characters not readily photographed the work has been
done by her.

DESCRIPTION OF GENERA AND .SPECIES
ARCHAOCYATHUS (ARCHAOCYATHELLUS) ATREUS, new species
Plate 8, figs. 2, 2a

This species is represented by two examples that are illustrated by
figures 2,2a. The specimen represented by figure 2 varies in diameter
from 2.2 mm. to 1.4 mm., and has a total length of 14 mm. A cross
section shows a thick outer wall (fig. 2’) but no structural detail, as
the calcite forming it is in a crystalline condition except in one place
of the section where there is a trace of what may have been two
septa. On the exterior surface in addition to the swelling of the wall
there are concentric growth lines and slight depressions; no cells
have been observed.

The nearest related species as indicated by exterior form is A.
(A.) dwighti Walcott’ from the Lower Cambrian of eastern New
York. Both are small undulating forms, but unfortunately no further
comparison can be made as we do not know the structure of the wall
OA.) atreus.

Formation and locality—Lower Cambrian: (62w) Mount Whyte
formation ; oolitic limestone, about 400 feet (123 m.) below summit
of ridge above Gog Lake, below Wonder Pass on Continental Divide,
in British Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta,
Canada.

*Tenth Ann. Rept. U. S. Geol. Survey, 1891, pl. 54, figs. 4, 4a.

68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Family Eocystipa Bather
Eocystid@ BATHER, 1900, Treatise on Zodlogy, Lankester, Pt. 3, p. 48.
GOGIA, new genus

All that is known of Gogia is included in the description of the
genotype, Gogia prolifica. The form of the calyx and the character
of the plates distinguish it from Eocystites as represented by the
single plate described by Billings or by the species E. ? ? longidac-
tylus Walcott,’ which is the only described species sufficiently well pre-
served to indicate what Eocystites may possibly include.

Genotype—Gogia prolifica Walcott.

Stratigraphic range-——As far as known Gogza is confined to a
massive band of calcareo-arenaceous shales 250 feet (76 m.) below
the oolitic limestone at the summit of the Mount Whyte formation of
the Lower Cambrian.

Geographic distribution—As far as known, it is confined to the
vicinity of Wonder Pass southwest of Banff, Alberta.

GOGIA PROLIFICA, new species
Plate 8, figs. 1, 1a-b

Calyx—Form: As seen flattened on the shale the outline is that of
a narrow isosceles triangle pointing downward. The stem is attached
to the apex of the triangle as inverted. A calyx 27 mm. in length has
a width across the top of 12mm. The largest specimen has a length
of 30mm. The plates of the calyx are polygonal, varying in size and
form. The outer surface of the plates appears to have been roughened
and the inner surface to have had a groove running from the central
depressed area out to each angle on the margin of the plate ; the casts
of these grooves are shown by figure 1a. The exterior of the plates
is known only from the casts in the shale as the plates have usually
been removed by solution of the calcite forming them.

The arms (eight on one specimen) are long, very slender, and
formed of numerous plates in a biserial arrangement and with a
narrow ambulacral furrow on the inner side.

The stem is slender, tapering gradually and formed of numerous
elongate and round, thick, tumid plates varying in size. The elongate
plates form the upper part of the stem to where it joins the calyx, and
the round plates the lower portion out to near the end where a group
of minute round plates occur. The round plates appear to have been
smooth, and the oval elongate plates tuberculated.

* Bull. U. S. Geol. Surv., No. 30, 1886, p. 94.

NOS FAUNA OF THE MOUNT WHYTE FORMATION 69

Observations —This genus and species differ from described
forms by the shape of the calyx and plates. The elongate arms and
stem resemble the arms and stem of Eocystites ? ? longidactylus
Walcott,’ but they differ in details.

So far as known to me, this is the oldest cystidian of this type. It
occurs at an horizon 1,000 feet (304.8 m.) or more below the zone of
Eocystites ?? longidactylus.

Formation and locality—Lower Cambrian: (62x) Mount Whyte
formation ; Silici-caleareous shale, on ridge above Gog Lake, below
Wonder Pass, on Continental Divide, in British Columbia, 19 miles
(30.4 km.) southwest of Banff, Alberta, Canada.

MICROMITRA (PATERINA) CHARON, new species
Plate 10, figs. 3, 3a-b

Some specimens of this species were confused with M. (P.)
wapta Walcott * when collected in the field. It differs from the latter
in form and in having a finely reticulated surface. It is more closely
related to M. (J.) pannula,’ but it differs in having a much more finely
reticulated surface and in the more elongate outline of the valves
when they are undistorted (see figs. 1, 1b)... The largest valve
observed has a length of 8 mm.

This shell is abundant on Mount Odaray at the type locality.

Formation and locality —Lower Cambrian: (61c) Mount Whyte
formation; dark siliceous shale, east slope of southeast ridge of
Mount Odaray, 7.5 miles (12 km.) south of Hector, on the Canadian
Pacific Railway, British Columbia, Canada.

OBOLUS DAMO, new species
Plate 10, figs. 6, 6a

This little shell is related to Obolus smithi from the Lower Cam-
brian Montevallo shales of Alabama, from which it differs in its
more circular outline. It also differs in the same manner from
another Lower Cambrian species, O. prindlei’ from the Olenellus-
bearing limestone of eastern New York.

The shells occur in a fine-grained, hard shaly arenaceous rock in
which very little of the original shell is preserved. The interior cast

*Bull. U. S. Geol. Survey, No. 30, 1886, p. 94, pl. 6, figs. 1, 1a-c. Pack:
Journ. Geol., Chicago, Vol. 14, 1906, p. 3, pl. 1, figs. I, Ia.

* Monogr. U. S. Geol. Survey, No. 51, 1912, p. 357.

*Tdem, p. 361, pl. 4.

*Tdem, p. 416.

*Idem, p. 409, pl. 27, figs. 3, 3a-e.

7O SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of a ventral valve shows a broad visceral area of the type of that in
Obolus apollinis Eichwald.*

Formation and locality—Lower Cambrian»: (63g) Mount Whyte
formation; greenish arenaceous shale, southwest slope of Mount
Temple, about 600 feet (184.6 m.) above base of Pinnacle Pass, and
1500 feet (461.5 m.) above upper portion of Paradise Valley, and
south of Lake Louise, Alberta, Canada.

ACROTHELE CLITUS, new species
Plate 10, figs. 4, 4a-c

This species differs from Acrothele colleni of the Ross Lake shale
of the Ptarmigan formation, with which I had identified it in my
field notes of 1908,” in having a uniformly smaller size and in the
presence in the dorsal valve of a very long and strong median ridge,
in this respect resembling Acrothele bellula of the Middle Cambrian
of Alabama.?

The largest specimens in the collection have a diameter of 4 mm.
and are very much flattened in the fine siliceous shale. The outer
surface is marked by concentric striz and lines of growth and a few
fine radiating lines.

Formation and locality Lower Cambrian: Mount Whyte forma-
tion; (35e) Lake Agnes shale, amphitheater between Popes Peak
and Mount Whyte, southwest of Lake Agnes and 3 miles (4.8 km.)
west-southwest of Lake Louise station, on the Canadian Pacific
Railroad, in western Alberta; also (57e) Mount Stephen section ;
just above the tunnel, north shoulder of Mount Stephen, 3 miles
(4.8 km.) east of Field, British Columbia, Canada.

WIMANELLA CATULUS, new species
Plate Io, figs. 5, 5a-c

This is a more elongate form than Wimanella simplex Walcott of
the Ptarmigan formation when specimens preserved in a similar
matrix are compared. This is best shown by examining figure 8,*
which illustrates a specimen of W. simplex from the limestone of the
Ptarmigan formation, and figures 5, 5b, plate io, illustrating W.
catulus in this paper. Several of the specimens from the two lime-
stones have the same outline, but in such instances the convexity of

1 Monogr. U. S. Geol. Survey, Vol. 51, 1912, pl. 7, figs. 1-6.

? Smithsonian Misc. Coll., Vol. 53, p. 214, 3 of section.

°U. S. Geol. Survey, Monogr. No. 51, 1912, pl. 58, figs. 5f, 5h.
* Smithsonian Misc. Coll., Vol. 67, 1917, pl. 4.

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 7x

the specimens is quite different. Thus figure 5, plate 10 (this paper)
is a strongly convex ventral valve and yet in outline it is much like
the dorsal’ valve represented by figure 8a, plate 4 (Vol. 67, No. 2,
Smithsonian Misc. Coll.).

The two species are closely related although there is about 500 feet
(152.4 m.) of limestone between their respective positions in the
section.

Of the known species of Wimanella three occur in strata referred
to the Lower Cambrian and four to the Middle Cambrian.

Formation and locality—Lower Cambrian: (63a) Mount Whyte
formation ; oolitic limestone about 130 feet (40 m.) above arenaceous
shaly beds; east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an
air line northeast of Lake Louise station on the Canadian Pacific
Railway, Alberta, Canada.

SHAFFERIA, new genus

The species on which this genus is based does not appear to fall
under any described genus. It has a carapace that suggests that of
Burgessia,’ but it has a thick, strong, and ornamented carapace, while
that of Burgessia is smooth and very delicate. It may be that I mis-
interpret the species and that it is one of the Discinocarina and the
notch is anterior and not posterior in position. The thick test and
deep notch certainly suggest its belonging with the Discinocarina.

All that is known of the genus is given under the description of the
type species.

Genotype.—Shafferia cisina Walcott.

Stratigraphic range.—This is limited to a thin layer of limestone
near the summit of the Mount Whyte formation.

Geographic distribution.—Southwest slope of Mount Shaffer on
trail to Lake McArthur, British Columbia, Canada.

The generic name is derived from Shaffer, the name of the moun-
tain from which Shafferia cisina was collected.

SHAFFERIA CISINA, new species
Plate 11, figs. 8, 8a

Of this species only a single carapace is known. This is bent over
along the median line and strongly notched posteriorly. The general
form is shown by figure 8 and a side view by figure 8a. The test is

* By misprint named ventral valve.
* Smithsonian Misc. Coll., Vol. 57, 1912, p. 177, pl. 27, figs. 1, 3.

72 SMITHSONIAN MISCELLANEOUS CCLLECTIONS VOL. 67

rather thick and marked by flat, irregular ridges that are subparallel
to the outer margin and almost transverse across the central portion.

The carapace is 3 mm. in length along the medial line and about
5 mm. in width.

Formation and locality—lLower Cambrian: (61d) Mount Whyte
formation ; oolitic limestone, southwest slope of Mount Shaffer on
Canyon side, on trail to Lake McArthur, 5.5 miles (8.8 km.) south
of Hector Station, on Canadian Pacific Railroad, British Columbia,
Canada.

AGRAULOS CHAROPS, new species
Plate 13, figs. 2, 2a

Species known from an imperfect cranidium.

Cephalon.—Cranidium small, evenly convex. Glabella a little
more than two-thirds the length of the cranidium, rather strongly
elevated along the medial line which is highest near the occipital ring
and slopes very gradually from the ring to the anterior extremity ;
dorsal furrows linear, distinct, gradually converging to the broadly
rounded anterior extremity which is about three-fourths as wide as
the base ; anterior furrow narrow and shallow ; glabellar furrows very
obscure; occipital groove rather broad, a little broader and more
shallow medially than laterally; occipital ring narrow laterally,
slightly expanded medially. Fixed cheeks low, wide and gently
convex, the distance from the palpebral lobe to the dorsal furrow
almost as great as the width of the glabella; postero-lateral lobe
imperfectly preserved; posterior groove narrow and quite deep at
the axial termination opposite the occipital ring, neither so narrow
nor so deep away from the axis, and cutting off an increasingly wider
posterior margin. Palpebral lobe small and inconspicuous, medial
in position with respect to the glabella exclusive of the occipital ring.
Palpebral ridge indicated only by the obtuse angulation of the cheek.
Frontal limb and border not clearly differentiated, the two together
forming a gently inclined frontal margin of approximately the same
width as the fixed cheek, exclusive of the postero-lateral lobe. Facial
sutures imperfectly preserved, the anterior section of the suture
merging smoothly into the anterior extremity.

Surface—Exterior surface minutely shagreened.

Dimensions.—Length of cranidium, 4.3 mm.; length of glabella,
3.0 mm.; width of glabella in front, 1.5 mm.; width of glabella at
base, 2.1 mm.

Type locality —(35£) Mount Stephen.

NOSa3 FAUNA OF THE MOUNT WHYTE FORMATION WS)

Observations —This species is unlike 4. (7) unca (fig. 1, pl. 13)
and A. stator (Smithsonian Misc. Coll., Vol. 67, 1917, pl. 6, fig. 6)
or any other species from the Lower Cambrian terrane.

Formation and locality—Lower Cambrian: (35f) Mount Whyte
formation; about 300 feet (95 m.) below the top of the Lower
Cambrian in bluish-black and gray limestone (18 feet=5.5 m.),
forming 6 of Mount Whyte formation; just above the tunnel, north
shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British
Columbia, Canada.

AGRAULOS (?) UNCA, new species
Plate 13, figs. I, Ia

Species known from cranidia.

Cephalon.—Cranidium very simple in outline, broadly and evenly |
rounded in front with two deltoid flanges at the base. Glabella
three-quarters or more as long as the cranidium, subcylindrical,
arcuate anteriorly; dorsal furrows linear, very faintly impressed,
roughly parallel; glabellar furrows obsolete; occipital groove rela-
tively broad but very shallow, uniform in depth between the dorsal
furrows; occipital ring moderately broad, expanded medially, not
nodose. Fixed cheeks and frontal limb and border not differentiated,
together forming a rather broad and evenly declining brim around
the glabella. Fixed cheeks rather narrow, the distance from the
palpebral lobe to the dorsal furrow a little more than half the width
of the medial portion of the glabella; postero-lateral lobe short and
wide, obtusely cuneate at the distal extremity. Palpebral lobe very
inconspicuous, defined merely by the outward arching in the facial
sutures, very short and slightly anterior with respect to the glabella.
Palpebral ridge faintly developed and not observable on most speci-
mens. Frontal limb and border about one-third the length of the
glabella, gently and evenly sloping, somewhat thickened toward the
periphery. Facial sutures obtusely V-shaped, aS anterior section
feebly arcuate. nes cheeks not preserved.

Bes on of cranidium, 2.5 mm.; width of cranidium
at base, 3.0 mm.; length of glabella, 1.5 mm.; width of glabella in
front, 1.9 mm. ; width of glabella at base, 2.0 mm.

Type locality—(61d) Mount Shaffer, British Columbia.

Observations —A graulos ? unca is exceedingly abundant at the
type locality, but has been rarely observed elsewhere. The first
comparison suggested is with Ptychoparia thia. It is a smoothed

74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

out, rounded form, differing in the practical absence of glabellar
furrows and palpebral ridges and in slight variations of the frontal!
limb and border. The two species are associated at locality 35f.
The generic reference is doubtful, but with only the cranidia for
study nothing better seems possible.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion; (61d) southwest slope of Mount Shaffer on Canyon side, on
trail to Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station,
on Canadian Pacific Railroad; and (35f) Mount Stephen section ;
about 300 feet (93.8 m.) below the top of the Lower Cambrian in
bluish-black and gray limestone, just dbove the tunnel, north shoulder
of Mount Stephen, 3 miles (4.8 km.) east of Field, both in British
Columbia, Canada.

CLENOPSIS CLEORA, new species
Plate 13, figs. 3, 3a

Species known from imperfect cranidia.

Cranidium.—Cranidium elongate. Glabella only about three-fifths
as long as the cranidium, rather strong, elevated along a low but
sub-acute ridge which becomes obsolete at some little distance behind
the anterior extremity; dorsal furrows quite broad and not very
deeply impressed, gradually converging so that the width at the
truncate anterior extremity is only about two-thirds of that at the
base ; glabellar furrows broad and shallow, obsolete upon the crest of
the glabella, the posterior and medial pairs oblique, the anterior pair
reduced to a couple of obscure lateral pits ; occipital furrow broad and
shallow, deepening a little toward the dorsal furrows ; occipital ring
low, flattened, moderately wide and carrying a small medial node.
Fixed cheeks low and broad, the distance from the palpebral lobe
to the dorsal furrow more than half the width of the medial portion
of the glabella; postero-lateral lobe imperfectly preserved, narrow
and probably petaloid at its extremity ; posterior furrow very shallow,
in line with the occipital ring. Palpebral lobe moderately elevated,
about one-third as long as the glabella, asymmetrically arcuate, sub-
medial in position with respect to the glabella. Palpebral ridge nar-
row, cordate, cutting somewhat obliquely across the fixed cheeks and
intercepting the dorsal furrows at the origin of the anterior glabellar
furrows. Frontal limb and border not sharply differentiated, the
profile in front of the glabella gently concave. Frontal limb narrow,
evenly declining medially, slightly convex laterally, cut off from the
border by a shallow, ill-defined groove. Frontal border very wide,

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 75

expanded medially, and broadly concave. Outline of facial sutures
and fixed cheeks not well preserved ; anterior portion of facial suture
apparently quite strongly arched.

Surface —Exterior surface shagreened with an exceedingly fine
and close granulation.

Dimensions.—Length of cranidium, 16.0 mm.; length of glabella,
9.4 mm.; width of glabella in front, 4.6 mm.; width of glabella at
base, 7.6 mm.

Type locality —(62w) Above Gog Lake, Wonder Pass. .

Observations.—There is a single pleural lobe of a thoracic segment
associated with the cranidia which may perhaps be referable to this
species. The segment is slender, not very deeply furrowed, and
bent backward at an obtuse angle about halfway between the prox-
imal and distal extremities.

The cranidium of this species recalls that of Olenopsis zoppi by its
broad frontal border, narrow frontal limb, elongate glabella and
strong palpebral ridge. It is quite distinct from any associated form
or forms from the same geological formation. It differs from O. ?
agnesensis* in shorter frontal limb and broad frontal border (see
figs. 5, 5a, pl. 13).

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion ; (62w) oolitic limestone, about 400 feet (123 m.) below summit
of ridge above Gog Lake, below Wonder Pass on Continental
Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff ;
(57S) about 160 feet (49 m.) below the Middle Cambrian, in gray
oolitic limestone, on Mount Bosworth, north of the Canadian Pacific
Railway between Hector and Stephen; and (63i) thin layer of sand-
stone ; between two eastern gullies on southern slope of Mount Bos-
worth, at about 6000-foot contour ; I mile (1.6 km.) west-northwest
of Stephen on the Canadian Pacific Railway, British Columbia.

OLENOPSIS CRITO, new species
Plate 11, figs. 6, 6a-b

Species known from detached portions of the cephalon.

Cephalon.—Cranidium large, and moderately convex. Glabella
three-fifths as long as the cranidium, slender, subconical in outline,
elevated along a rather prominent medial ridge which persists
almost to the anterior extremity ; dorsal furrows shallow but distinct,
rounding sharply into the more shallow anterior furrow; anterior

*Smithsonian Misc. Coll., Vol. 57, 1912, p. 242, pl. 36, fig. 2.

76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

extremity broadly rounded and half as wide as the base; posterior
and medial pairs of glabellar furrows broad, deeply impressed, sub-
equal and parallel to one another, extending obliquely backward and
disappearing abruptly a little more than halfway up the lateral slope ;
third pair linear, transverse, shorter and much more shallow than
those behind it ; and an anterior pair indicated by slight indentations
close to the dorsal furrow; occipital groove very shallow medially,
similar in character laterally to the posterior glabellar furrows;
occipital ring slightly expanded medially and apparently bearing near
the posterior margin a very inconspicuous medial node. Fixed cheeks
low, flattened, and very wide, the distance from the palpebral lobe to
the dorsal furrow almost as great as the width of the medial portion
of the glabella; postero-lateral lobe slender and elongate, probably
acutely angulated at its distal extremity. Palpebral lobe imperfectly
preserved, crescentic, approximately one-third the length of the
glabella, the posterior end of the lobe on a line with the base of the
posterior glabellar furrows. Palpebral ridge obscure, narrow,
cordate, arching obliquely across the cheek and intercepting the
dorsal furrows directly in front of the third pair of glabellar furrows.
Frontal limb wide, very gently declining in front of the glabella, but
-rather steeply in front of the palpebral ridge. Frontal border also
wide and gently concave, delimited from the limb by a low cord-like
ridge. Facial sutures imperfectly preserved, posterior section ex-
tended outward at from 10° or 15° off the transverse line ; anterior
section also oblique and gently convex. Associated free cheek
rather broad; inner portion of about the same width as the border,
arching gently away from the palpebral lobe; border very wide, not
conspicuously differentiated, produced posteriorly into moderately
long, acutely tapering genal spines.

Surface.—Character of exterior surface not preserved.

Dimensions.—Length of a large cranidium, 25.0 mm.; length of
glabella, 15.0 mm.; width of glabella in front, 6.6 mm.; width of
elabella at base, 13.0 mm.

Type locality —(6o0e) Ptarmigan Pass.

Observations.—This is the largest species of the genus Olenopsis
from the Mount Whyte formation. It compares in size with O.
americanus of the Gordon shale,’ but it differs from that species in the
character of the frontal limb and border and elongate postero-lateral
limb of the cranidium. It occurs about 700 feet (213 m.) lower in

1See Smithsonian Misc. Coll., Vol. 67, 1917, p. 37, pl. 6, figs. 8, 8a-b.

I GiGY 8 FAUNA OF THE MOUNT WHYTE FORMATION Ti

the section than O. americanus. O. crito is unlike either O. ?
agnesensis, O. cleora, or O. leuka, of the Mount Whye formation.

Formation and locality —Lower Cambrian: (60e) Mount Whyte
formation ; about 75 feet (22.8 m.) from the base of the formation ;
Ptarmigan Lake Pass at head of Corral Creek, 6 miles (9.6 km.)
northeast of Laggan, Alberta, Canada.

OLENOPSIS LEUKA, new species
Plate 13, fig. 4

Species known from imperfect cranidia.
Cranidium.—Glabella approximately two-thirds the length of the
-cranidium, trapezoidal in outline, broadly convex ; anterior extremity
broadly rounded and almost three-fourths the width of the base;
dorsal furrows linear, deeply impressed, evenly converging ; glabellar
furrows almost obsolete, owing probably to the absence of the outer
test; traces of the posterior and medial pairs preserved in some
individuals in the form of lateral pits, just within the dorsal furrows,
the posterior pair somewhat elongated oblique to the axis; occipital
groove rather narrow, partially dissecting the crest of the glabella
and deepening toward the dorsal furrows; occipital ring of an
elevation similar to that of the glabella, expanded medially; the
median node if originally present has been destroyed. Fixed cheeks
plump and wide, the distance from the palpebral lobe to the dorsal
furrow approximately equal to the width of the medial portion of
the glabella ; postero-lateral lobe imperfectly preserved, rather nar-
row, moderately extended, obtusely tapering at the distal extremity ;
posterior groove quite deep, broadening away from the axis and
cutting off an increasingly wider posterior margin. Palpebral lobe
also imperfectly preserved but apparently low, short and submedial
with respect to the glabella. Palpebral ridge obscure. Frontal limb
narrow, flattened medially, merging into the fixed cheeks laterally.
Frontal border defined by a shallow groove, thickened, upturned,
and slightly expanded medially so that the width in front of the
glabella is greater than that of the limb. Free cheeks unknown
but probably narrow and produced posteriorly into slender spines.
Other characters not preserved.

Surface—Exterior surface unknown owing to the character of
the matrix, a fine and very tough quartzitic sandstone.

Dimensions.—Length of cranidium, 7.5 mm.; length of glabella,
4.8 mm.; width of glabella in front, 2.3 mm.; width of glabella at
base, 3.0 mm.

Type locality —(58g) Mount Bosworth.

73 SMITHSONIAN MISCEILLANEOUS COLLECTIONS VoL. 67

Observations.—The groove which separates the frontal limb from
the border is obsolete medially, and the rim often has the appearance
of being slightly produced posteriorly directly opposite the glabella.
This character recalls P. lux, a smaller species with a more slender
glabella, quite sharply rounded at the anterior extremity. The
obscurity of the glabellar furrows is probably due in large measure
to the character of the matrix, a rather firm quartzitic sandstone.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion; (58g) about 200 feet (60 m.) below the top of the Olenellus
zone in sandstones and shales, a few yards north of the Canadian
Pacific Railroad track, midway between Stephen and Hector, on
south slope of Mount Bosworth, British Columbia, Canada.

PTYCHOPARIA ADINA, new species
Plate 12, figs. 3, 3a-b

Species known from the cranidia and associated free cheeks,
pygidia and disjointed thoracic segments.

Cephalon.—Cranidium small and approximately twice as broad at
the base as it is long. Glabella quite strongly elevated along an
obtuse median ridge, about three-quarters of the length of the
cranidium, elongate-trapezoidal in outline, the squarely truncate
anterior extremity only a little more than two-thirds as wide as the
base ; dorsal furrows linear, deeply impressed, evenly converging ;
anterior furrow not quite so deep as the lateral furrows; glabellar
furrows very obscure, in most individuals practically obsolete, indi-
cated in others by very feeble depressions toward the dorsal furrows,
the posterior pair oblique, the medial and anterior pairs at right
angles to the axis of the shield; occipital furrow moderately broad
and quite deep, especially toward the dorsal furrows; occipital ring
rather broad, expanded medially and bearing, midway between the
margins, a small node. Fixed cheeks rising obliquely from the
dorsal furrows, moderately wide, the distance from the palpebral
lobe to the dorsal furrow approximately half the width of the medial
portion of the glabella; postero-lateral lobe rather wide, extended
laterally and obtusely angulated at the distal extremity; posterior
furrow deeply channeled, cutting off an increasingly wider posterior
margin away from the axis. Palpebral lobe not greatly elevated,
rather short, contained a little less than three times in the length of
the glabella, quite strongly crescentic, slightly anterior in position.
Palpebral ridge obscure, somewhat oblique to the axis, intercepting
the dorsal furrows a little behind the anterior extremity. Frontal

NO 3 FAUNA OF THE MOUNT WHYTE FORMATION 79

limb of moderate width, moderately convex. Frontal border cut off
from the limb by a shallow linear groove, not so wide as the limb,
flattened but not thickened. Facial sutures imperfectly preserved,
apparently a rather symmetric W, the posterior section oblique, the
base convex, the anterior section broadly arcuate. The associated
free cheeks moderately wide, rather plump, the peripheral margin a
flattened band cut off from the rest of the cheek by an ill-defined
groove; outer margin abruptly constricted posteriorly and produced
into very slender acutely tapering genal spines.

Thorax.—Thoracic segments rather narrow, deeply sulcated
medially, slender and acutely falcate at their distal extremities.

Pygidium.—Associated pygidium comparable in dimensions to the
cephalon, rudely lenticular in outline. Axial lobe broad, strongly
-convex, obtusely truncate at the posterior extremity ; axial annula-
tions distinct anteriorly, obscure posteriorly, indicating 4 component
segments and a terminal section. Pleural lobes of approximately the
same width anteriorly as the axial, wedging out posteriorly ; pleural
furrows rudely parallel to the anterior margin, increasingly shallow
toward the posterior extremity. Peripheral rim narrow, smooth,
defined only by the abrupt disappearance of the pleural grooving.
Posterior extremity very broadly rounded or obtusely truncate.

Surface -—Exterior surface microscopically granulated.

Dimensions.—The largest cranidium in the collection has a length
of 8 mm., but the average size is 4 mm. or less in length.

Type locality —(57q) Mount Bosworth, British Columbia.

Observations.—The limestone at the type locality is densely packed

with the cranidia, free cheeks, and less frequently the thoracic seg-
ments and pygidia of this species.
_ P. lux, of the Mount Whyte formation, has a more slender glabella,
which tapers to a rounded anterior extremity instead of being
squarely truncate as in P. adina; furthermore, the fixed cheeks are
wider in Jux than in adina, the palpebral lobe is not placed so far
forward, the frontal limb is narrower medially, and the frontal
border is expanded and tends to be somewhat produced posteriorly
directly opposite the anterior extremity of the glabella. P. adina is
quite distinct from P. thia and Agraulos ? unca.

Formation and locality—lLower Cambrian: (57q) Mount Whyte
formation ? (Mount Bosworth section) ; drift block supposed to be
from about 200 feet (61.2 m.) below the top of the Lower Cambrian
in bluish-gray limestone (60 feet) forming 16c in Mount Whyte

80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

formation, slopes of Mount Bosworth, a little north of the Canadian
Pacific Railway track, between Stephen and Hector, British Colum-
bia, Canada.
PTYCHOPARIA CARINA, new species
Plate 13, figs. 6, 6a

Species known from a single imperfect cranidium.

Cranidium.—Cranidium apparently short and broad. Glabella not
far from three-quarters the length of the cranidium, moderately
broad and moderately elevated along an obtuse medial ridge which
becomes obsolete at some little distance behind the anterior extremity ;
dorsal furrows rather shallow; anterior extremity of the glabella
more strongly rounded than the frontal border and only about two-
thirds as wide as the base; glabellar furrows conspicuously deep, the
posterior pair much more produced than the medial and more
strongly oblique; medial pair short, but deeply gouged toward the
dorsal furrows; anterior pair reduced to a couple of obscure lateral
pits; character of occipital furrow and ring not preserved. Fixed
cheeks low and broad, the distance from the palpebral lobe to the
dorsal furrow more than half the width of the medial portion of the
glabella; postero-lateral lobe imperfectly preserved but apparently
slender and elongated ; posterior groove rather broad and moderately
deep. Palpebral lobe not preserved but probably short, inconspicu-
ous and placed far back, in line with either the posterior glabellar
furrows or the posterior lobe of the glabella. Palpebral ridge narrow,
cordate, arching obliquely across the fixed cheeks and intercepting
the dorsal furrows at some little distance behind the anterior ex-
tremity. Frontal limb flattened, very narrow medially. Frontal
border a rather broad fillet, cut off from the limb by a sharply defined
groove, and a little wider medially than the limb. Other characters
not preserved.

Surface —Exterior surface shagreened with a fine and close granu-
lation; a few coarser macroscopic granules scattered sparsely over
the surface of the cranidium.

Dimensions —Length of cranidium, 13.2+ mm.; length of gla-
bella, 9.5-+mm.; width of glabella in front, 4.5 mm.; width of gla-
bella at base, 6.8mm.

Type locality—(35m) 3 miles (4.8 km.) southwest of head of
Lake Louise, Alberta.

Observations —This species has such a thickly granulated and
pustulose surface and such a strong frontal border that it is readily
distinguished from other species of this horizon and fauna. The

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 81

granulation recalls that of P. permulta, a species occurring in the
Albertella shale about 700 feet (213.4 m.) higher in the section.

Formation and locality —Lower Cambrian: (35m) Mount Whyte
formation ; 3 miles (4.8 km.) southwest of the head of Lake Louise,
on east slope of Mount Whyte, Alberta, Canada.

PTYCHOPARIA (?) CERCOPS, new species
Plate 12, figs. 1, 1a-d

Species known from imperfect cranidia, free cheeks, and pygidia.

Cephalon.—Cephalon not found entire. Cranidium large, feebly
contoured. Glabella long relatively, almost four-fifths the length of
the cranidium, slightly elevated along a narrow but rather distinct
ridge which becomes obsolete at some little distance behind the
anterior extremity; dorsal furrows shallow, gradually converging
toward the broadly arcuate anterior extremity; glabellar furrows
broad and exceedingly obscure, the posterior pair oblique, the medial
pair transverse to the axis, the anterior pair probably very short, and
parallel to the medial furrows, but in the majority of individuals
entirely obsolete; occipital furrow very broad and very shallow
especially upon the crest of the glabella; occipital ring low and
flattened, expanded medially, bearing near the posterior margin a
small but prominent node. Fixed cheeks low, narrow, the distance
from the palpebral lobe to the dorsal furrow a little less than half
the width of the medial portion of the glabella; postero-lateral lobe
wide, cuneiform, obtusely angulated at the distal extremity, not quite
twice as long as its greatest width; posterior groove broad and shal-
low, narrowest and deepest toward the dorsal furrow, its proximal
extremity in line with the occipital ring. Palpebral lobe very incon-
spicuous, very short, only about one-fifth as long as the glabella,
scarcely at all elevated, and placed far forward opposite the ante-
rior glabellar furrows. Palpebral ridge not defined, obscurely
suggested. Frontal limb and border slightly differentiated from one
another, the profile between the anterior extremity of the glabella
and the outer margin gently concave. Facial sutures rudely and
asymmetrically V-shaped, the posterior arm oblique, the anterior
arm broadly and quite strongly arched. Associated free cheeks low
and broad, gently and smoothly convex, bordered by a wide and ill-
defined band, and without traces of genal spines.

Thorax.—Associated thoracic segments of moderate width. Axial
lobe not preserved. Pleural segments flexuous, posteriorly directed
and acutely falcate at their distal extremities; pleural furrows

82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

obsolete toward the axis, very deeply channeled medially, gradually
wedging out distally; anterior margin a little narrower and more
sharply elevated than the posterior.

Pygidium.—Associated pygidia twice as broad as long. Axial
lobe broadly but not very strongly arched, subcylindrical, obtusely
tapering posteriorly, rather sharply annulated even to the posterior
extremity, including, apparently, 4 component segments. Pleural
lobes differentiated from the axial merely by the contour, not cut
off by incised furrows; annular ridges of the axial lobe persistent
across the pleura, for the most part without change in direction or
character, the posterior ridges, however, obsolete upon the pleura.
Peripheral rim narrow, flattened, reduced to a mere thread pos-
teriorly, widening gradually toward the thorax. Posterior extremity
sharply rounded. .

Surface——Exterior surface shagreened but not distinctly gran-
ulated.

Dimensions —Length of a cranidium, 20.4 mm. ; length of glabella,
16.1 mm.; width of base of glabella, 12.5 mm.; width of front of
glabella, 6.3 mm.

Type locality — (63c) Ptarmigan Peak. /

Observations —The cranidium of P. cercops Walcott is relatively
large and relatively long, and the relief upon the cranidium is con-
spicuously low. It is quite abundant at the type locality, but is not
found commonly elsewhere.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion; (63c) 85 feet (26 m.) up in alternating oolitic limestone and
thin-bedded compact sandstones forming 1 of section, and (63a)
oolitic limestone about 130 feet (40 m.) above arenaceous shaly
beds ; both from east base of Ptarmigan Peak, 5.5 miles (8.8 km.)
in an air line northeast of Lake Louise station on the Canadian
Pacific Railway, Alberta, Canada.

Small cranidia in a compact shaly sandstone matrix from the
Mount Whyte horizon of Castle Mountain appear to be identical
with cranidia of similar size of this species. Locality 58t, Lower
Cambrian: Mount Whyte formation; sandy shale about 150 feet
(45.7-m.) below the Middle Cambrian, just below the big cliff on
the east shoulder of Castle Mountain, north of the Canadian Pacific
Railway, Alberta.

Somewhat similar cranidia occur in the oolitic limestone of Ross
Mountain, but they have a slightly more distinct glabellum and are

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 83

not quite so much smoothed out. Locality 63k, Lower Cambrian:
Mount Whyte formation; above and southeast of Ross Lake, 1 mile
(1.6 km.) south of Stephen, Canadian Pacific Railway, on Con-
tinental Divide, British Columbia, Canada.

PTYCHOPARIA (?) CLEADAS, new species
Plate 12, fig. 2

Species known from cranidia.

Cephalon —Cranidium minute, angular in outline, narrow and
truncate in front, relatively wide at the base. Glabella long, ap-
proximately three-fourths the length of the cranidium, quite strongly
elevated along the sharply rounded medial ridge, trapezoidal in out-
line; dorsal furrows linear, incised, converging with a moderate
degree of rapidity toward the squarely truncate anterior extremity ;
glabellar furrows rather obscure, the posterior pair inclined to the
median axis at an angle of about 45°, not persistent across the crest
of the glabella, the medial pair a little shorter and less oblique, and
the anterior pair much reduced and in some individuals entirely
obsolete; occipital groove narrow and deep, uniform in character
between the dorsal furrows; occipital ring flattened, constricted
laterally, widely expanded medially and bearing near the posterior
margin a small medial node. Fixed cheeks wide and evenly declining
from the dorsal furrows; postero-lateral lobe very wide, deltoid in
outline, probably obtusely angulated at its distal extremity ; posterior
furrow narrow but deeply incised, cutting off an increasingly wider
posterior margin away from the axis. Palpebral lobe imperfectly
preserved but apparently very short, inconspicuous, and placed far
forward opposite the medial glabellar furrows. Palpebral ridge
very narrow but usually distinct, arching across the fixed cheeks and
intercepting the dorsal furrows directly behind the anterior ex-
tremity of the glabella. Frontal limb narrow, flattened. Frontal
_border a little wider than the limb, thickened, cordate, and somewhat
expanded medially. Facial sutures very imperfectly preserved, the
posterior section very long relatively and probably oblique, the
anterior arm short and probably arcuate. Other characters not
preserved.

Surface —Exterior surface felt-like.

Dimensions.—Length of cranidium, 2.0 mm.; length of glabella,
1.5 mm. ; width of cranidium at base, 3.0+ mm. |

Type locality —(57s) Mount Bosworth.

84 SMITHSONIAN MISCELLANEOUS COLLECTIONS . VOL. 67

Observations —P. (?) cleadas Walcott may be readily separated
from other species of the genus by its very small size and angular
outline, its sharply defined trapezoidal glabella, its very small anterior
eye placed far forward and the consequently very wide posterior lobe,
its very narrow limb and almost equally narrow cordate border
roughly parallel to the base of the cranidium.

These carbon-black cranidia, though so minute, show up quite
well in the gray limestone of the type locality.

The specimens from the arenaceous shale at Ptarmigan Pass
(Locality 60e) are in the form of casts and do not show the glabellar
furrows, but this appears to result from the condition of preserva-
tion. The glabella is also relatively shorter than that of the specimen
illustrated but not shorter than some of those in the same hand
specimen of limestone containing the type specimen.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion; (578) about 160 feet (49 m.) below the Middle Cambrian,
near the base of the gray oolitic limestone, on Mount Bosworth,
north of the Canadian Pacific Railway between Hector and Stephen,
on the Continental Divide between British Columbia and Alberta ;
(58u) drift block supposed to have come from about 240 feet
(73.8 m.) below the top of the Lower Cambrian in limestone inter-
bedded in sandstone (31 feet) ; slopes of Mount Bosworth, a little
north of the Canadian Pacific Railway track, between Stephen and
Hector, British:Columbia; also (60e) about 75 feet (22.8 m.) from
the base of the Mount Whyte formation; Ptarmigan Lake Pass at
head of Corral Creek, 6 miles (9.6 km.) northeast of Laggan, Alberta,
Canada.

PTYCHOPARIA CLEON, new species

Plate 12, fig. 10

Species known from an imperfect cranidium.

Cephalon—Cranidium small and moderately convex. Glabella
low, elevated along an obscure median ridge which is moderately
elevated posteriorly and increasingly lower anteriorly; dorsal fur-
rows linear, rather shallow, converging so that the width of the
truncate anterior extremity is about three-fifths of that at the base;
elabellar furrows obscure, the posterior and medial pairs subparallel,
disappearing about halfway up to the median line; anterior pair
obsolete ; occipital groove rather shallow, deepening slightly toward
the dorsal furrows; occipital ring imperfectly preserved. Fixed
cheeks low, wide, the distance from the palpebral lobe to the dorsal
furrow more than half the width of the medial portion of the

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 85

glabella; postero-lateral lobe imperfectly preserved but probably
strong and moderately extended; posterior groove very narrow
toward the axis, terminating opposite the occipital ring, broader and
more shallow away from the axis, and cutting off an increasingly
wider posterior margin. Palpebral lobe narrow, crescentic, contained
about three times in the length of the glabella, in line with the pos-
terior glabellar furrows. Palpebral ridge oblique, defined only by
the angulation of the cheek, not outlined by a raised cord or liration.
Frontal limb rather narrow in front of the glabella and flattened,
rather steeply declining in front of the palpebral ridge. Frontal
border narrow, thickened, the medial portion posteriorly produced
and acutely angulated. Facial sutures imperfectly preserved; an-
terior section apparently very strongly convex.

Surface——Exterior surface microscopically shagreened. Vena-
tion upon the frontal limb very fine.

Dimensions—Length of cranidium, 3.5 mm.; length of glabella,
2.5 mm.

Type locality.—(35f) Mount Stephen.

Observations —The cranidium of this species is much like that of
Ptychoparia thia except that the frontal limb is longer in front of
the glabella and there is a swelling or elongate tubercle on the
frontal rim opposite the glabella. The species is known only by a
single specimen of the cranidium from the limestone at the type
locality (35f).

Formation and locality.—Lower Cambrian: (35f) Mount Whyte
formation; about 300 feet (95 m.) below the top of the Lower
Cambrian in bluish-black and gray limestone (18 feet=5.5 m.) form-
ing 6 of Mount Whyte formation; just above the tunnel, north
shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British
Columbia, Canada.

PTYCHOPARIA CLUSIA, new species
Plate 11, figs. 3, 3a

Species known from imperfect cranidia.

Cephalon.—Glabella a little more than two-thirds as long as the
cranidium, quite strongly elevated along a subacute medial ridge
which disappears gradually toward the front; outline trapezoidal,
the broadly rounded anterior extremity not more than half as broad
as the base; dorsal furrows rather wide, deeply impressed, converg-
ing quite rapidly anteriorly and rounding sharply into the more
shallow, transverse anterior furrow; glabellar furrows also broad

86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

and deep, though not persistent across the crest; posterior pair
inclined to the axis of the shield at an angle of a little more than 45°,
almost completely isolating the tumid posterior lobe; medial pair
neither so broad nor so deep as the posterior and nearly at right |
angles to the axis; anterior pair a little shorter than the medial,
slightly inclined toward the front and placed nearer to the medial
pair than to the anterior furrow; occipital groove broad and deep,
completely dissecting the crest of the glabella, very slightly sinuous ;
occipital ring rather narrow, expanded medially, obtusely angulated
at the medial posterior margin, and bearing a rather prominent
medial node. Fixed cheeks plump and quite wide, the distance from
the palpebral lobe to the dorsal furrow a little more than half: the
width of the medial- portion of the glabella; postero-lateral lobe
narrow and probably extended laterally ; posterior furrow conspicu-
ously broad and deep, its inner terminus in line with both the occipital
furrow and ring; posterior margin narrow and sharply elevated.
Palpebral lobe short, narrow, crescentic, set opposite the lobe between
the posterior and medial furrows. Palpebral ridge rather prominent,
cordate, arching across the fixed cheeks and intercepting the dorsal
furrows directly in front of the anterior glabellar furrows. Frontal
limb rather narrow, inflated laterally, gently declining medially.
Frontal border wider medially than the limb, sharply upturned.
Facial sutures imperfectly preserved.

Surface —Exterior surface very finely and closely granulated or
roughened by an irregular pitting with broken, depressed ridges that
give the effect of obscure granulation.

Dimensions —Length of cranidium, 7.5 mm.; length of glabella,
5.25 mm.; width of glabeila in front, 2.0 mm.; width of glabella at
base, 4.2 mm.

Type locality—(58k) Mount Stephen.

Observations.—The glabella of this species recalls that of P.
gogensis and less:‘so that of P. pia (pl. 12, figs. 4 and 8). ~The
frontal border is quite unlike that of either of the two species.

Formation and locality—lLower Cambrian: (58k) Mount Whyte
formation ; just above the tunnel, north shoulder of Mount Stephen,
3 miles (4.8 km.) east of Field, British Columbia, Canada.

PTYCHOPARIA COSSUS, new species
Plate 11, figs. 5, 5a
Species known from an imperfect cranidium.
Cephalon—Cranidium small, moderately convex. Glabella a little
more than ‘three-fourths as long as the cranidium, moderately

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 87

elevated along an obtuse median ridge, relatively broad; dorsal fur-
rows well rounded and quite deep, converging so that the rounded
truncate anterior extremity is only a little more than two-thirds
as wide as the base; anterior furrow shallow and not sharply defined ;
elabellar furrows rather obscure and not persistent to the crest of the
glabella, the posterior pair oblique, the medial pair more nearly
horizontal, the anterior pair slightly inclined toward the anterior
extremity ; occipital furrow sinuous, arched forward upon the crest,
deepening toward the dorsal furrows; occipital ring not preserved.
Fixed cheek low, flattened, the distance from the palpebral lobe to
the dorsal furrow a little more than half the width of the glabella ;
postero-lateral lobe imperfectly preserved, narrow and elongate ; pos-
terior groove narrow but well rounded, in line with the occipital ring.
Palpebral lobe very short, not very prominent, in line with the pos-
terior glabellar furrows. Palpebral ridge low, cordate, cutting
obliquely across from the palpebral lobe and intercepting the dorsal
furrows at the origin of the anterior glabellar furrows. Frontal
limb narrow and flattened in front of the glabella. Frontal border
wide, slightly convex, somewhat thickened, the inner margin almost
at right angles to the axis, the outer margin strongly arcuate. Facial
sutures imperfectly preserved.

Surface —Exterior surface minutely shagreened.

Dimensions —Length of cranidium, 8.0 mm.; length of glabella,
5.5 mm.

Type locality—(61a) Yoho Canyon.

Observations—The glabella of this species recalls that of P.
cuneas, but the frontal limb differs in being narrower and in having
a gently convex surface.

Formation and locality Lower Cambrian: (61a) Mount Whyte
formation ; gray oolitic siliceous limestone; Yoho Canyon, 1.5 miles
(2.4 km.) above mouth of Yoho River and about 5.5 miles (8.8 km.)
from Field on Canadian Pacific Railway, British Columbia, Canada.

PTYCHOPARIA CUNEAS, new species
Plate 11, figs. 4, 4a

Species known from an imperfect cranidium.

Cephalon.—Glabella relatively short, only about two-thirds as long
as the cranidium, moderately convex, trapezoidal in outline; dorsal
furrows moderately deep, rounding rather sharply into the shallow
‘groove which outlines the truncated anterior extremity. Glabellar
furrows imperfect; posterior pair rather broad, shallow and ex-

88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

tending obliquely inward to a low, strong medial ridge that continues
nearly to the front of the glabella; the medial and anterior pairs
transverse; occipital groove broad and. shallow upon the summit
of the glabella, narrow and deep toward the dorsal furrows ; occipital
ring moderately elevated and expanded medially, bearing a small
but rather sharp medial node. Fixed cheeks slightly convex, the
distance from the palpebral lobe to the dorsal furrow approximately
half the width of the medial portion of the glabella ; postero-lateral
lobe rather narrow, posterior groove narrow, deep, its axial terminus
in line with the occipital ring. Palpebral lobe short, crescentic, not
very prominent, placed rather far back opposite the posterior gla-
bellar furrows. Palpebral ridge low and ill-defined, it arches ob-
liquely across the fixed cheek and intercepts the dorsal furrow a
little behind the anterior extremity. Frontal limb narrow, flattened
in front and merging into the fixed cheeks laterally. Frontal border
slightly elevated, flattened, and with a shallow, transverse median
depression, slightly expanded both along the outer and the inner
margin, wider than the frontal limb and cut off from it by a shallow
sulcus. Facial sutures imperfectly preserved ; anterior section gently
arcuate.

Surface—Exterior surface exhibiting a felt-like texture.

Dimensions —Length of cranidium, 8.0 mm.; length of glabella,
5.1 mm.; width of glabella in front, 2.7 mm.; width of glabella at
base, 4.5 mm.

Type locality —(35£) Mount Stephen.

Observations.—The broad, short glabella and broad frontal border
of this species serve to distinguish it from other species of Ptycho-
paria from the Mount Whyte formation. The frontal border has
a slight resemblance to that of P. gogensis (pl. 12, fig. 4). The
short, broad glabella recalls that of some undescribed species from
the Lower Cambrian of the St. Lawrence Valley.

‘Formation and locality—lLower Cambrian: (35f) Mount Whyte
formation (Mount Stephen section); about 300 feet (93.8 m.)
below the top of the Lower Cambrian in bluish-black and gray
limestone, just above the tunnel, north shoulder of Mount Stephen,
3 miles (4.8 km.) east of Field, British Columbia, Canada.

PTYCHOPARIA GOGENSIS, new species
Plate 12, figs. 4, 4a

Species known from imperfect cranidia.
Cranidium.—Cranidium large and relatively broad, the maximum
width exclusive of the free cheeks more than double the length;

———————

NOS FAUNA OF THE MOUNT WHYTE FORMATION 89

glabella prominent, nearly three-fourths as long as the cranidium,
conspicuously elevated along an obtuse medial ridge; dorsal furrows
broad and deeply channeled, slowly converging toward the front;
anterior extremity of glabella approximately two-thirds as wide as
the base, obtusely truncate, and outlined by a shallow groove;
glabeliar furrows deep on the sides of the glabella but entirely
obsolete upon the crest; posterior pair broad and deep, obliquely
arcuate; medial pair not so deep as the posterior; anterior pair
obscure, set very close to the medial pair ; lobe between the occipital
groove and the posterior pair of furrows quite strongly elevatea,
that between the posterior and medial pairs also rather prominent ;
occipital furrow broad, and quite deep, especially towards the dorsal
furrows; occipital ring narrow, somewhat expanded medially; a
median node is suggested by what appears to have been a broken-off
base of a tubercle. Fixed cheeks rising abruptly from the dorsal
furrows, then arching gently to the palpebral lobe, the distance from
the palpebral lobe to the dorsal furrow more than half the width of
the medial portion of the glabella; postero-lateral lobe slender and
petaloid; posterior groove deep, broadening away from the axis,
nearly in line with the occipital furrow. Palpebral lobe rather short,
crescentic, moderately prominent, and placed opposite the posterior
elabellar furrows. Palpebral ridge obtuse, cutting somewhat ob-
liquely across the fixed cheeks and intercepting the dorsal furrows
near the origin of the anterior glabellar furrows. Frontal limb very
narrow and quite steeply declining medially, broadly inflated laterally.
Frontal border separated by a shallow sulcus, nearly flat at the center
and slightly concave at the sides posteriorly produced opposite the
glabella and obtusely angulated.

Surface—Exterior surface,imperfectly preserved, but apparently
shagreened by a fine granulation.

Dimensions —Length of cranidium, 14.0 mm. ; width of cranidium
at base, 30.0+ mm.; length of glabella, 10.0 mm.; width of glabella
in front, 5.5 mm.; width of glabella at base, 8.5 mm.

Type locality —(62w) Above Gog Lake, Wonder Pass.

Observations.—The more widely distributed P. pia is much smaller
and not so coarse as P. gogensis, but it has much the same general
appearance. The glabella of P. gogensis is more elevated and pro-
portionally broader, the dorsal furrows are more deeply channeled,
the glabellar furrows are also deeper, and the posterior and medial
glabellar lobes consequently higher. The relative width of the fixed
cheeks is approximately the same in both species, but they are lower

go SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

in P. pia. There is a further resemblance in the outline of the
frontal rim, but in P. fia the rim is thickened and flattened, while
in P. gogensis it is not thickened and it is concave at the sides.

Formation and locality—Lower Cambrian: Mount Whyte for-
mation ; (62w) oolitic limestone, about 400 feet (123 m.) below
summit of ridge above Gog Lake below Wonder Pass on Continental
Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff,
Alberta.

PTYCHOPARIA LUX, new species

Plate 12, fig. 5

Species known from cranidia.

Cephalon.—Relative proportions of cephalon varying quite widely,
the length in the majority of individuals more than half the greatest
width. Glabella short and rather slender, quite strongly elevated
along an obtuse medial ridge which disappears a little behind the
anterior extremity ; dorsal furrows quite deeply impressed, converg-
ing with a moderate degree of rapidity toward the arcuate anterior
extremity ; curvature of front of glabella usually a little greater than
that of the frontal margin ; width of front of glabella only about half
the width of the base of the glabella; glabellar furrows exceedingly
obscure and in most individuals entirely obsolete, sometimes indicated
by very feeble lateral depressions just within the dorsal furrows;
occipital groove narrow, persistent across the crest of the glabella
but deepening toward the dorsal furrows; occipital ring moderately
broad, flattened, expanded medially, and bearing near the posterior
margin a small node. Fixed cheeks broad and plump, the width
from the palpebral lobe to the dorsal furrow equal, approximately,
to the width of the medial portion of the glabella; postero-lateral
lobe very narrow, moderately extended, petaloid at the distal ex-
tremity; posterior groove in line with the occipital ring, widening
away from the axis and cutting off an increasingly wider posterior
margin. Palpebral lobe not very prominent, contained about two
and one-half times in the length of the glabella, feebly arcuate, sub-
medial with respect to the glabella. Palpebral ridge narrow, and
very obscure, curving obliquely across the fixed cheeks and inter-
cepting the dorsal furrows a little behind the anterior extremity.
Frontal limb narrow, flattened medially, feebly inflated laterally.
Frontal border crescentic, wider medially than the frontal limb, and
often somewhat produced posteriorly, cut off from the limb by a
groove rather sharply impressed laterally but often very obscure
medially. Facial sutures imperfectly preserved; posterior section

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION gI

rudely transverse to the axis, medial section relatively short, anterior
section strongly convex.

Other characters of the cephalon and the thorax not preserved.

Surface Exterior surface shagreened with a microscopically fine
but rather sharp granulation.

Dimensions —Length of cranidium, 4.0 mm.; length of glabella,
3.0 mm.; width of glabella in front, 1.5 mm.; width of glabella at
base, 2.0 mm.

Type locality—(61d) Mount Shaffer.

Observations.—See observations under P. adina.

P. lux is very common at the type locality.

Formation and locality —Lower Cambrian: Mount Whyte forma- .
tion; (61d) southwest slope of Mount Shaffer on Canyon side, on
trail to Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station,
on Canadian Pacific Railroad, British Columbia, Canada.

PTYCHOPARIA PEROLA, new species
Plate 12) figs. 7, 7a

Dorsal shield—Dorsal shield small, elongate-oval in outline, flat-
tened in the shale but probably quite strongly contoured originally.
Axial lobe rather slender, arched well above the pleura and cut
off from them by rather deep furrows.

Cephalon.—Cephalon about one-third as long as the dorsal shield,
rudely semicircular in outline. Glabella of moderate dimensions,
subrectangular or trapezoidal in outline, that of the type a little
broader relatively than in the average individual; medial ridge low
and obtuse, dorsal furrows deeply impressed, evenly converging
toward the squarely truncate anterior extremity; glabellar furrows
quite broad and moderately deep, but not persistent across the crest ;
posterior pair somewhat oblique; medial and anterior pairs almost
at right angles to the axis, the anterior pair reduced, however, to
nothing more than a couple of lateral pits; occipital groove partially
dissecting the crest of the glabella, deeply impressed toward the
dorsal furrows; occipital ring narrow, expanding slightly medially,
and bearing near the posterior margin a small sharp node. Fixed
cheeks low and moderately wide, the distance from the palpebral lobe
to the dorsal furrow a half or a little more than half as wide as the
medial portion of the glabella; postero-lateral lobe rather short,
broad, and trigonal, quite acutely angulated at its distal extremity ;
posterior furrow broad and quite deep, almost in line with the oc-
cipital furrow. -Palpebral lobe inconspicuous, almost straight, very

Q2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

slightly elevated, and less than one-third as long as the glabella
including the occipital ring, placed rather far forward, opposite the
medial glabellar furrows. Palpebral ridge narrow, sharply defined,
cutting across the fixed cheeks almost at right angles to the axis and
intercepting the dorsal furrows a little behind the anterior extremity
of the glabella. Frontal limb rather narrow, slightly inflated, cut
off from the flattened frontal border by a shallow groove parallel
to the anterior extremity of the glabella. Frontal border thus form-
ing a chord about two-thirds the length of the base of the cranidium,
the medial portion of which is of approximately the same width as
the medial portion of the frontal limb. Facial sutures interrupted
medially by the small palpebral lobes, the posterior arm oblique, the
anterior arm broadly convex. Free cheeks narrow, smoothly convex,
bordered by a flattened band produced posteriorly into short, acutely
tapering genal spines.

Thorax—Thoracic segments 15 in number. Axial lobe quite
strongly convex, very strongly annulated. Pleural segments com-
pactly arranged, the flattened portion between the obtuse geniculation
and the axial furrows not quite so wide, as a rule, as the axial lobe.
Pleural furrows almost as wide as the including segment excepting
toward the axis where they are narrower and anterior in position;
anterior margin of the segment a little more sharply elevated than
the posterior; extremities of segments imperfectly preserved but
probably attenuated and acutely falcate. .

Pygidium.—Associated pygidium small, short and broadly lenti-
cular in outline. Axial lobe rather coarse, subcylindrical, tapering
slightly toward the obtuse posterior extremity ; annulations distinct,
indicating possibly two component segments and a terminal section.
Pleural lobes drooping, of approximately the same width anteriorly
as the axial lobe, obscurely furrowed with one or two shallow
grooves, parallel to the arcuate anterior margin. Peripheral rim
narrow, flattened, obscurely defined ; periphery broadly rounded, often
obtusely truncate at the posterior extremity.

Surface.—Exterior surface shagreened but apparently not granu-
lated.

Dimensions —Length, 17.0+ mm.; greatest width, 10.0+ mm.

Type locality —(35m) Mount Whyte.

Observations —This is one of the relatively narrow, elongate
forms of the genus that suggests P. cordillere of the Middle Cam-
brian. It differs from the latter species in having a stronger frontal
border on the cephalon, less elongate glabella, narrower frontal limb,

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 93

15 thoracic segments instead of 18 or 19, and a narrower pleural
thoracic lobe. It is most nearly related to P. candace * of the Middle
Cambrian Albertella fauna of Gordon Creek, Montana, from which
it differs in having a narrower frontal limb in front of the glabella
and a less elongate glabella; otherwise the two species closely
resemble each other.

All the specimens of P. perola are compressed in a hard siliceous,
finely arenaceous shale from which the test of the trilobite has been
removed, and the replacement shows only a finely roughened surface
that may be a reproduction of the original surface, or it may be
roughened by the fine-grained matrix having been impressed in
the original test.

The largest dorsal shield has a length of 20 mm. The proportions
of the various parts are well shown by figure 7, the original of which
has a length of 16 mm. The relatively large cranidium, elongate
thorax, and very small pygidium are finely brought out in this figure.

Formation and locality—lLower Cambrian: (35m) Mount Whyte
formation; Lake Agnes shale, 3 miles (4.8 km.) southwest of the
head of Lake Louise on the east slope of Mount Whyte; also (35e)
amphitheater between Popes Peak and Mount Whyte, southwest
of Lake Agnes, and 3 miles (4.8 km.) southwest of the head of Lake
Louise Station on the Canadian Pacific Railroad, both in western
Alberta, Canada.

PTYCHOPARIA PIA, new species
Plate 12, fig. 8

Species known from imperfect cranidia and associated thoracic
segments.

Cramdium.—Cranidivum relatively short and broad, dissected by
the dorsal furrows into three subequal areas. Glabella rather large
relatively, quite prominently elevated along a very obtuse medial
ridge which disappears a little behind the anterior extremity ; dorsal
furrows deeply channeled, converging to a slight degree toward the
rounded truncate anterior extremity, so that the front of the glabella
is not very much more than two-thirds as wide as the base. Glabellar
furrows broad and, toward the dorsal furrows, moderately deep,
obsolete, however, upon the summit of the glabella; posterior pair
oblique, the medial pair a little shorter and at right angles to the axis,
the anterior pair still shorter and rather obscure, transverse or
inclined slightly toward the front; posterior and medial glabellar

1S.ee pl. 6, fig. 3, Smithsonian Misc. Coll., Vol. 67, 1917.

O04 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

lobes quite prominently elevated ; occipital furrow broad, partially
dissecting the crest of the glabella, deepening toward the dorsal
furrows; occipital ring rather narrow, expanding medially and
bearing on well-preserved individuals a small median node. Fixed
cheeks wide and plump, the distance from the palpebral lobe to the
dorsal furrow only a little less than the width of the medial portion
‘of the glabella; postero-lateral lobe rather narrow and extended,
somewhat falcate at its extremity ; posterior furrow deeply concave,
narrow toward the axis, broadening away from it, and cutting off
an increasingly wider posterior margin. Palpebral lobe short, cres-
centic, quite prominently elevated, submedial or slightly anterior
in position, with respect to the glabella. Palpebral ridge obscure,
extending obliquely across the fixed cheeks and intercepting the
dorsal furrows near the margin of the anterior glabellar furrows.
Frontal limb narrow, evenly declining, in some individuals obscurely
truncated. in front of the glabella. Frontal border cut off from the
limb by a shallow, ill-defined groove, narrow laterally but widening
medially and slightly produced posteriorly so that in front of the
glabella the border is wider than the limb. Facial sutures imperfectly
preserved, the posterior section somewhat flexuous, the anterior
section broadly arcuate. Associated free cheeks low and broad,
bordered by a thickened cordate rim, cut off from the rest of the
cheek by a shallow groove, and produced posteriorly into rather }
short, acutely tapering spines.

Thorax.—Associated thoracic segments rather wide, deeply chan-
neled, the anterior margin undercut ; extremities falcate.

Surface—Exterior surface crowded with an irregular, very fine
granulation which on slightly worn individuals assumes a felt-like
aspect. :

Dimensions —Length of cranidium, 14.2 mm.; length of glabella,
9.8 mm.; width of glabella in front, 5.0 mm.; width of glabella at
base, 8.5 mm.

Type locality —(35£) Mount Stephen.

Observations —P. pia Walcott is, perhaps, the most widely dis-
tributed member of the genus in the Mount Whyte formation. There
are no described forms which approach close to P. pia, though P.
gogensis and P. skapta resemble it in general outline and contour,
and in the relative proportions of the glabella. P. gogensis, however,
is almost double the dimensions of P. pia, the glabella is more
convex, the dorsal and glabellar furrows are deeper, the fixed
cheeks higher, and the frontal rim upturned but not thickened as in

MOS 3 FAUNA OF THE MOUNT WHYTE FORMATION 95

pia. P. skapta, on the other hand, is only about half the size of pia,
and the frontal rim is very much narrower relatively and much more
thickened than in pia.

Formation and locality—Lower Cambrian: (35f) Mount Whyte
formation (Mount Stephen section); about 300 feet (93.8 m.)
below the top of the Lower Cambrian in bluish-black and gray
limestone ; just above the tunnel, north shoulder of Mount Stephen,
3 miles (4.8 km.) east of Field; (35h) about 375 feet: (114 m.)
below the Middle Cambrian, in shales of the Mount Whyte forma-
tion, on Mount Bosworth, north of the Canadian Pacific Railway
between Hector and Stephen, on the Continental Divide between
British Columbia and Alberta; (63k) north spur of Mount Whyte,
above and southeast of Ross Lake, 1 mile (1.6 km.) south of
Stephen, Canadian Pacific Railway on Continental Divide ; and (57r)
just above the tunnel, north shoulder of Mount Stephen, 3 miles
(4.8 km.) east of Field.

A cranidium that may belong with this species occurs in the lime-
stone of (3) of the Mount Stephen section, about 180 feet (54.8 m.)
above the horizon of the type specimen, which occurs in (4) of that
section:* Lower Cambrian: (57e) Mount Whyte formation; about
115 feet (35 m.) below the top of the Lower Cambrian near the top
of the dark bluish-gray limestone (53 feet=16 m.) forming 3 of
Mount Whyte formation, just above the tunnel, north shoulder of
Mount Stephen, 3 miles (4.8 km.) east of Field, all in British
Columbia, Canada.

PTYCHOPARIA SKAPTA, new species
Plate 12, figs. 9, 9a

Species known from an imperfect cranidium.

Cramdium.—Cranidium small, rather strongly contoured. Gla-
bella relatively large, trapezoidal in outline, the anterior extremity
truncate and approximately three-fourths as wide as the base ; dorsal
furrows linear, quite deeply incised; anterior furrow distinct but
not so deep as the dorsal; glabellar furrows dissecting the sides of
the glabella but entirely obsolete upon the crest; posterior pair more
produced and more strongly oblique than the medial; anterior pair
reduced to a couple of small pits just within the dorsal furrows;
occipital groove narrow, very shallow upon the crest of the glabella,
deep toward the dorsal furrows ; occipital ring imperfectly preserved,
narrow on the sides and widening towards the center. Fixed cheeks

‘Canadian Alpine Journ.,; Vol. i, 1908, pp. 240-242.

y6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

also imperfectly preserved but certainly wide and rather plump;
postero-lateral lobe known only from the proximal portion ; posterior
groove in line with the occipital ring. Palpebral lobe not preserved.
Palpebral ridge low and narrow, arching obliquely across the fixed
cheeks and intercepting the dorsal furrows directly behind the
anterior extremity of the glabella. Frontal limb flattened and in
front of the glabella almost obliterated, expanded laterally, cut off
from the frontal border by a wide and angular channel. Border
thickened, elevated, rather narrow laterally, expanded medially.
Other characters not preserved.

Surface —Exterior surface finely granular.

Dimensions —Length of cranidium, 4.5 mm.; length of glabella,
3.2 mm.; width of glabella in front, 1.8 mm.; width of glabella at
base, 2.4 mm.

Tvpe locality—(62w) Above Gog Lake, Wonder Pass.

Observations—P. skapta is, unfortunately, described from a
unique type. P. pia, a much larger form, is probably the most closely
allied of the known species. They resemble one another in the
general contour, the outline of the glabella, the wide fixed cheeks,
and the thickened frontal limb, posteriorly produced and angulated
medially. P. skapta is, however, only about half as large as P. pia,
the medial ridge of the glabella is a little more elevated, the dorsal
and glabellar furrows are more deeply incised, the fixed cheeks more
plump, the frontal limb much more reduced, and the frontal border
heavier but not so wide.

Formation and locality —Lower Cambrian: (62w) Mount Whyte
formation ; oolitic limestone, about 400 feet (123 m.) below summit
of ridge above Gog Lake below Wonder Pass on Continental Divide,
in British Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta,
Canada.

PTYCHOPARIA THIA, new species

Plate 12, fig. 6

Species known from imperfect cranidia.

Cramdium.—Glabella small relatively, broadly convex, rudely
trapezoidal in outline, quite truncate in front, the sides roughly
parallel; dorsal furrows shallow and not sharply defined; glabellar
furrows narrow, occasionally distinct but never conspicuous, obsolete
upon the crest of the glabella ; posterior pair oblique, the medial pair
diverging slightly from the horizontal, the anterior pair normal to
the axis; occipital groove moderately broad and moderately deep,
uniformly depressed throughout its extent; occipital ring rather

Se Se Se Se tr th

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION Q7

narrow, expanded medially, moderately elevated, not nodose. Fixed
cheeks low and broad, and gently convex; postero-lateral lobe im-
perfectly preserved; posterior groove narrow and not very deep.
Palpebral lobe short but quite prominent, feebly crescentic, placed
quite far back in line with the lobe between the posterior and medial
furrows. Palpebral ridge narrow and very obscure, arching obliquely
across the fixed cheeks and intercepting the dorsal furrows directly
behind the anterior extremity of the glabella. Frontal limb and
border imperfectly differentiated, the two together of about the same
width as the fixed cheeks and contoured very much like them.
Frontal border a little more thickened and consequently a little more
elevated than the limb, the medial portion posteriorly produced into
an obtuse angle which closely approximates the anterior extremity
of the glabella. Facial sutures imperfectly preserved, the anterior
segment probably arcuate. Other characters not preserved.

Surface —Exterior surface shagreened but not granulated.

Dimensions—Length of cranidium, 4.2 mm.; length of glabella,
2.9 mm.; width of glabella in front, 2.0 mm.; width of glabella at
base, 1.5 mm.

Type locality—(35h) Mount Bosworth.

Observations—The diagnostic characters of the species are the
rudely rectangular glabella, the wide, gently convex fixed cheeks,
and the ill-differentiated border and limb which together with the
cheeks form a frame about the glabella of approximately uniform
width and convexity.

Ptychoparia thia is smaller than either P. lux or adina; the fixed
cheeks are much wider than in adina; the glabella is broader relatively
and less tapering anteriorly, and the frontal border is much more
obscurely differentiated than in lux. The distribution is wider in
thia than in either of the other species in question.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion; (35h) about 375 feet (114 m.) below the Middle Cambrian, in
shales, on Mount Bosworth, north of the Canadian Pacific Railway
between Hector and Stephen, on the Continental Divide between
British Columbia and Alberta; (35f, 58k) just above the tunnel,
north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field,
British Columbia; 35f is near the base of the Mount Whyte
formation in stratum 6 and 58k about 295 feet (89.9 m.) above
near the summit of the formation in stratum 1;' and (62w) oolitic
limestone, about 400 feet (123 m.) below summit of ridge above

*Canadian Alpine Journ., Vol. 1, 1908, pp. 240-242.

98 SMITHSONIAN MISCELLANEOUS COLLECTIONS - VOL. 67

Gog Lake below Wonder Pass on Continental Divide, in British
Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta, Canada?

PTYCHOPARIA, species undetermined

Fragments of the cranidia of what may be three species of
Ptychoparia occur in the Mount Whyte formation, none of which
have been identified with known species. As the genus is well
represented by the described species I shall not now describe or
illustrate the fragments.

Genus CREPICEPHALUS Owen
Crepicephalus OwEN, 1852. For synonymy and discussion of this genus see
Smithsonian Mise. Coll., Vol. 64, 1916, pp. 199-204.

At the time I was studying the species referred to Crepicephalus
the specimens of the species from the Mount Whyte formation and
from the Mount Bosworth section were not to be found. The two
species from the Mount Whyte formation are from the upper beds
a short distance beneath the Middle Cambrian Ptarmigan formation.
They are C. cecinna (pl. 11, figs. 1, 1a) and C. celer (pl. 11, fig. 2).
The first species belongs to the C. iowensis* group of species, and
C. celer to the C. unca form, both of which are well represented in
the Upper Cambrian. The two species from the Pioche formation
of Nevada, C. augusta and C. liliana,’ correspond in type, as far
as we know them, to the Mount Whyte formation species, C. cecimna
and C. celer, which occur at an horizon that is characterized by a
Lower Cambrian fauna, although at the localities at which they
were found neither of the genera Olenellus or Mesonacis was found
in association with them. Very little attention was paid to searching
for any particular grouping of species and the collections made
except at two or three localities were very limited. The association
of species that have been found with Crepicephalus and with Olenel-
lus or Mesonacis is as follows. The localities are numbered and a
similar number placed on each specimen.

1 Smithsonian Misc. Coll., Vol. 64, 1916, p. 201.
*Idem, pl. 35, figs. 1d, 1e.
* Idem, pl. 20, figs. 5, 6.

WO? 3 FAUNA OF THE MOUNT WHYTE FORMATION 99

58k 61d 62w 63a
Names Mount Mount Gog Ptarmigan
Stephen Shaffer Lake Pass

Archeocyathus (A.) atrets ........ a SK

Micromitra (Paterina) labradorica.. x< x

Micromitra (Iphidella) pannula..... x x

Kutorgina cf. cingulata............. AS iy x

Acrotreta sagittalis taconica........ ~< x x ee

Nisusia (Jamesella) lowi........... x x x

Wimawella catulus 2... ...00 ccs ces es oe * SK

FNelavOMella (CLONGALG ocwes seers oc < be SK

FeV aevellemas De itt coe 2 ot oes ee acelale be »< ée

DIGEITELIC UOVIGMS. cv cara ce cece oo s SK «~ Sé

OTOP WOKELIONSD: | sce cisicccte es ot ne S By ae

inolusnes*DuIWesy i. those). cos cee le x x x

TV OUMGEWELUES SP WM tis «osc ejsiehe cso oe rr x

SHOR COSCO PRE A OE Ene o4

PAE UNOS MUNGUIA », ovarac.e 6-216 « 0 da erse.si oa = Se

Olenopsis AZNeSENSIS .........00005% ail Ee

GUeWO PSUS CLEOTON «2.5 s\iarye sas ee Fare ye 4

PADGONENOIMESAIST obec ciel cleta's «ghee a ' << Af

UV GHOPATIO. GEVCOPS .lacweige oss ce : tre <

EN GHOPOIUOCCUUSUGS Shs cians Shs a oan Se ae

PEVCNOPAVIG Cl. GOZCUSHS s. 0008 050's ny x

PEG MGMOPUTUG WU. we cet ce cue ase sores Se

PN GOPOMMG: SICUDLO) a ss siecle ses om se 6 | >

EENGOPOMIGUTIAG See taha sii tle ahs aes | < a

Crepicephalus cecinna ........8..05 oes * SK

Grepicephalus <Celer <6 sicnsrncn soos DA im

ID OFUPY SC NGMNG 03% 22 ce sidee o nas a3 <

Corynexochus senectus ...........- me

WRESONGCIS SUDCTI. «202i. ss ece stat Ae x

Bathyuriscus (Poliella) primus .. oe

CREPICEPHALUS CECINNA, new species

Plate 11, figs. I, 1a-b

Species known from a cranidium and a few associated pygidia.

Cranidium.—Cranidium short and_ broad.

Glabella relatively

large, subtrapezoidal in outline, a little less than five-sixths as long
as the cranidium, and about four-fifths as wide in front as it is at the
base; dorsal furrows deeply impressed, terminating anteriorly in
small pits; anterior furrow not quite so deep as the dorsal, very
feebly arcuate; glabellar furrows moderately broad and quite deep,
not persistent, however, across the low medial ridge; posterior pair
a little more strongly oblique than the medial; anterior pair obscure,

100 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

much shorter than the furrows behind them and nearly at right
angles to the axis of the shield; occipital furrow sinuous, deep dis-
tally, bent forward upon the crest of the glabella and only partially
dissecting it ; occipital ring very narrow laterally, expanded medially,
bearing near the posterior margin a small sharp node. Fixed cheeks
low and broad, the distance from the palpebral lobe to the dorsal
furrow decidedly more than half the width of the medial portion of
the glabella; postero-lateral lobe not preserved but necessarily
narrow; posterior furrow narrow, deep. Palpebral lobe not pre-
served, apparently small, not very prominent and placed far back
opposite the posterior lobe of the glabella. Palpebral ridge narrow,
cordate, quite sharply elevated, curving obliquely across the fixed
cheeks, and intercepting the dorsal furrows a little behind the an-
terior extremity, thus enclosing a rudely elliptical area interrupted
by the glabella. Frontal limb narrow medially, of approximately the
same width as the thickened cordate frontal border, from which it
is separated by a narrow but rather deeply incised groove. Other
characters of the cephalon not preserved.

Pygidium.—Pygidium short and broad, the lateral margins diverg-
ing slightly posteriorly, the anterior and posterior margins exclusive
of the spines roughly parallel. Axial lobe rather low and flattened
upon its summit, obtusely truncate posteriorly ; axial annulations
quite distinct anteriorly, somewhat flexuous, indicating 5 or 6 compo-
nent segments and a terminal section; pleural lobes exclusive of the
spines, moderately convex, deeply furrowed, the grooves increasingly

shallow and more closely spaced posteriorly ; interspaces elevated

parallel to the anterior lateral margin, the anterior ridges obtusely
angulated and nodose at the angles, gradually dying out along an
arc of about 180°; postero-lateral extremities flattened and pro-
duced into slender, slightly diverging spines of approximately the
same length as the axial lobe of the pygidium.

Surface —Exterior surface very finely granulated; a few much
coarser granules scattered over the frontal limb and border.

Dimensions —Length of cranidium, 4.3 mm.; length of glabella,
3.5 mm.; width of glabella in front, 2.0 mm.; width of glabella at
base, 2.5 mm.; length of pygidium exclusive of the terminal spines,
5.0 mm. ; length of pygidium including the terminal spines, 10.0 mm. ;
width of medial portion of pygidium, 8.5 mm.

Type locality —(63a) Ptarmigan Peak.

Observations.—Two distinct systems of surface sculpture are
developed in this species, a fine, close granulation over the entire
surface and a coarse, sparse granulation upon the frontal limb and

NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION IOI

border and probably upon the pygidium. P. carina, the only other
form which has a similar surface, is much larger and the glabella is
much more strongly rounded anteriorly than in C. cecinna,

Both the cranidium and associated pygidium of this species are
closely related to Crepicephalus upis of the Upper Cambrian Gallatin
limestone of Montana.’ They are also closely related in form to
C. liliana,’ from strata referred to the upper zone of the Lower
Cambrian of Nevada. C. cecinna is not closely related to C. chares
of the Ptarmigan formation.

Formation and locality —Lower Cambrian: Mount Whyte forma-
tion ; (63a) oolitic limestone about 130 feet (40 m.) above arenaceous
shaly beds; east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an
air line northeast of Lake Louise station on the Canadian Pacific
Railway, Alberta; also (62w) oolitic limestone, about 400 feet
(123 m.) below summit of ridge above Gog Lake below Wonder Pass
on Continental Divide, in British Columbia, 19 miles (30.4 km.)
southwest of Banff, Alberta, Canada.

CREPICEPHALUS CELER, new species
Plate 11, fig. 2

Species known from the pygidium. :

Pygidium.—Pygidium rudely quadrate in outline exclusive of the
posterior constriction, the lateral margins approximately parallel
to the axis; anterior margin broken by the forward curve of the
axial lobe; posterior margin very broadly and deeply insinuated.
Axial lobe large and coarse, broadly conic in outline, acutely tapering
posteriorly; axial annulations probably very distinct in perfectly
preserved individuals, including apparently 6 component segments
and a terminal section. Pleural lobes flexuous, irregular in outline,
the anterior lateral margin an obtuse right angle; pleural furrows
following the same general direction as the outer margin but less
angulated, disappearing abruptly along an imaginary arc of about
180° ; extremities of pleural lobes produced into cuneate appendages,
acutely tapering.

Surface.—Exterior surface unknown.

Dimensions.—Length of pygidium including: the lateral spines,
19.5 mm.; length of pygidium to the medial posterior margin, 12.5
mm. ; greatest width of pygidium, 15.0 mm.

* Smithsonian Mise. Coll., Vol. 64, Ka pl. 33, figs. 4, 4a-d.

7 Idem, pl. 29, figs. 5, 5a-c.
*Tdem., Vol. 67, 1917, pl. 6, figs. 5; 5a-c.

102 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Type locality —(58k) Mount Stephen.

Observations,—C. celer is represented by a single specimen of a
large pygidium of the C. chares* type from the Ptarmigan formation.
It differs from the pygidium of the latter species in having a much
larger axial lobe; in this character it approaches C. unca of the
Upper Cambrian of Minnesota.’

A small cranidium associated with the pygidium may belong to
this species, but it is too imperfect to identify even as belonging to
the genus.

Formation and locality—Lower Cambrian: Mount Whyte forma-
tion; (58k) about 5 feet (1.5 m.) below the top of the Lower Cam-
brian in thin-bedded bluish-black and gray limestone, just above the
tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of
Field, British Columbia, Canada.

DORYPYGE DAMIA, new species
Plate 11, figs. 7, 7a

Species known from imperfect cranidia and pygidia.

Cephalon.—Glabella broadly -and rather strongly convex, sub-
cylindrical in outline and slightly contracted anteriorly ; dorsal fur-
rows narrow but quite deeply impressed, terminating anteriorly in a
couple of small pits; anterior furrow very narrow and separating a
wire-like border from the glabella ; anterior extremity rounded; gla-
bellar furrows reduced to a posterior and medial pair of short shallow
linear depressions just within the dorsal furrows; occipital furrow
almost obsolete upon the summit of the glabella, narrow but quite
deeply incised towards the dorsal furrows ; occipital ring moderately
wide, imperfectly preserved. Fixed cheeks also imperfectly pre-
served, rather narrow, and gently convex; groove of postero-lateral
lobe quite broad but not very deep, in line with the occipital ring.
Palpebral lobe not preserved. Palpebral ridge feebly indicated by
an obtuse angulation of the cheek a little behind and parallel to the
anterior extremity. Frontal limb practically obsolete in front of
the glabella. Other characters unknown. :

Pygidium.—Associated pygidium rather large, semielliptical in
outline. Axial lobe quite strongly convex, of approximately the
same width as the pleural lobe; tapering gradually toward the
obtusely -rounded posterior extremity which falls just within the
peripheral rim; axial annulations coarse and distinct even toward

1 Smithsonian Misc. Coll., Vol. 67, 1917, pl: 6, figs. 5, Se.
2Idem. Vol. 64, 1916, pl. 35, figs. 1d, Ie.

Nor 3 FAUNA OF THE MOUNT WHYTE FORMATION 103

the posterior extremity, indicating 5 component segments and a
terminal section. Pleural lobes flattened; traces of the anchylosed
segments still retained in the broad and shallow pleural grooves,
which become increasingly shallow and approach more and more
closely to the axis of the shield toward the posterior extremity.
Peripheral rim narrow, flattened and with 5 very sharp short spines
on each side which are more strongly inclined posteriorly; they
correspond in number and position to the component anchylosed
segments.

Surface.—Exterior surface finely granulated.

Dimensions —Length of type cranidium, 11.0+ mm.; length of
glabella, 10.0+ mm.; width of glabella at base, 7.0+ mm.; length of
pygidium exclusive of serrations, 11.0+ mm.; width of pygidium
anteriorly, exclusive of serrations, 18.0+ mm.

Type locality—(62w) Wonder Pass.

Observations—The cranidium of this species at once recalls that
of Dorypyge richthofeni Dames, from China.” It differs in its finer
squamose granulation. The associated pygidia are also quite unlike
those associated with the Chinese species.

Formation and locality —Lower Cambrian: (62w) Mount Whyte
formation; No. 1 of section; oolitic limestone; about 400 feet
(123 m.) below summit of ridge above Gog Lake below Wonder
Pass on Continental Divide, in British Columbia, 19 miles (30.4 km.)
southwest of Banff, Alberta, Canada.

+ Research in China, Carnegie Inst. of Washington, Pub. No. 54, Vol. 3. 1913,
pl. 8, figs. 1, 10.

104. SMITHSONIAN MISCELLANEOUS COLLECTIONS VCL. 67

DESCRIPTION (OF -PLATIES

Gogia *prolifica Walcott. «20.22... < +a sb... ees Suse's ssn oie oe ee 68
Fic. 1. (Natural size.) Calyx with 5 arms and outline of stem. U. S.
National Museum, Catalogue No. 64350.

Ia. (XX 3.) Stem and calyx of the specimen illustrated by fig. 1D.
The plates have been removed by solution, so that the cast
of the inner surface of the plate of the calyx and of the
outer surface of the plates of the stem is shown.

1b, (Natural size.) Calyx, stem and arms of specimen shown by
fig. Ia. A small calyx is seen on the upper end of the piece
of rock. Note the long arms. U. S. National Museum,
Catalogue No. 64351.

The specimens represented by figs. 1, 1a-b, are from locality
62x, Lower Cambrian: Mount Whyte formation; above Gog

Lake, Wonder Pass, British Columbia.

Archeocyathus (Arche@ocyathellus) atreus Walcott.........0ceeeeeeeeees 67
Fic. 2. (xX 4.) Portion of a slender corolla with matrix of its ex-
tension.
2’. Cross section of fig. 2, showing thickness of wall.

2a. (X4.) Anirregular corolla with strong undulations of growth.
(This is on the same block with fig. 2.) U. S. National
Museum, Catalogue No. 64352.
The specimens represented by figs. 2, 2a, are from locality 62w,
Lower Cambrian: Mount Whyte formation; above Gog Lake,
Wonder Pass, British Columbia.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 3, PL. 8

LOWER CAMBRIAN CYSTIDS

RON Rt:

Te
é

Aa f' i)
nal UD oh
A tLe
mK ee Pu
Li 1 \ ,

106 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 19

Corynexochus senecius Billings)... 0.2 3.0. eee. = Js eee on ie eee
Fics. 1, 1a. (X3.) Dorsal view and side outline of cranidium with
most of test exfoliated. U.S. National Museum, Catalogue
No. 62726.
1b, tc. (X4.) Dorsal and side view of a pygidium. U. S.
National Museum, Catalogue No. 62731.

1d. (X4.) Small pygidium. U.S. National Museum, Catalogue |

No. 62733.
From limestone at locality 411, Lower Cambrian: Bonne Bay,
Newfoundland.
The specimens represented by figs. 1, ta-d have been figured by
Walcott, Smithsonian Misc. Coll. Vol. 64, No. 5, 1916, pl. 56, figs.
I, 1’, 1, te’, and 1f, respectively.

2, 2a. (X3.) Dorsal and side views of a partially exfoliated

cranidium, with slight indication of lateral glabellar fur-
rows. U.S. National Museum, Catalogue No. 62722.
2b, 2c. (3 3.) An associated pygidium that has been slightly
elongated. U. S. National Museum, Catalogue No. 62723.
From locality 61d, Lower Cambrian: Mount Whyte formation ;
southwest slope of Mount Shaffer, British Columbia.
The specimens represented by figs. 2, 2a-c, have been figured by
Walcott, Smithsonian Misc. Coll., Vol. 64, No. 5, 1916, pl. 55, figs.
7, 7', 74, and 7a’, respectively.

Mesonacis vermontana (Hall) v2. accescacs see snes cineca ee ee eee
Fic. 3. (Natural size.) An entire dorsal shield from the type locality
(25) at Georgia, Vermont, showing 14 thoracic segments
of the Olenellus type, the spine-bearing segment, and ten
segments of the Mesonacis type. U.S. National Museum,

Catalogue No. 15399a.

From locality 25, Lower Cambrian: Siliceous or finely arenaceous
shale just above Parker’s quarry, Georgia township, Franklin
County, Vermont.

The specimen represented by fig. 3 has been figured by Walcott,
Smithsonian Misc. Coll., Vol. 53, No. 6, 1910, pl. 26, fig. 1; also idem,
Vol. 64, No. 5, 1916, pl. 45, fig. 2.

Mesonacss gilberts (Mee) . oissiccs ce oloesn'ss oo aie visas nee e ee
Fic. 4. (About % natural size.) - The illustration is taken from a
plaster cast of the specimen now in the Geological Museum
of Princeton University, Princeton, New Jersey, which was
from locality 35n, Lower Cambrian: Mount Whyte forma-
tion; eastern slope of Mount Odaray, above McArthur
Pass, British Columbia. Plastotype. U. S. National
Museum, Catalogue No. 626109.
The specimen represented by fig. 4 has been figured by Walcott,
Smithsonian Misc. Coll., Vol. 64, No. 5, 1916, pl. 45, fig. 3.

NO. 3, PL. 9

VOL. 67,

‘SMITHSONIAN MISCELLANEOUS COLLECTIONS

LOWER CAMBRIAN TRILOBITES

Lats itn

a ,| wa

ae fait

wep yt

" eae 7)

AL ae ial

Pig wi) is.) im ;
by hy Wy Wiad Th

108 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67 ©

DESCRIPTION OF PLATE 10

Corynexochus (Bonnia) parvulus (Billings) .............2.0eeee: = israel
Fics. 1, Ia. (X3.) Dorsal and side views of a finely preserved
cranidium. U.S. National Museum, Catalogue No. 62744.
1b, 1c. ‘XX 3.) Dorsal and side views of a pygidium. U. S.
National Museum, Catalogue No. 62745.
From the limestone of locality 41k, Lower Cambrian: Forteau
Bay, Labrador.

The specimens represented by figs. I, Ia-c, have been figured by.

Walcott, Smithsonian Misc. Coll., Vol. 64, No. 5, 1916, pl. 57, figs. 1D,
1b’, Ic, and Ic’, respectively.

Corynexochus (Bonnia) feldensts (Walcott)...........0-- 0+ +«+ss een
Fics. 2, 2a. (X3.) Dorsal and side views of the type cranidium.
U. S. National Museum, Catalogue No. 62751.
2b, 2c. (X3.) Dorsal and side views of a pygidium associated

with the cranidium represented by fig. 2. U. S. National
Museum, Catalogue No. 62752.
From the limestone locality 351, Lower Cambrian: Ptarmigan
Pass, Alberta.
The specimens represented by figs. 2, 2a-c have been figured by
Walcott, Smithsonian Misc. Coll., Vol. 64, No. 5, 1916, pl. 57, figs.
4, 4’, 4a, and 4a’, respectively.

Micromitra (Paterina) charon Walcott...........00cccecccceunsccecteas
Fic. 3. (X 3.) Ventral valve flattened by compression in the siliceous
shale. U.S. National Museum, Catalogue No. 64353.
3a. (X4.) Flattened dorsal valves, one of which shows the
reticulated surface. U. S. National Museum, Catalogue
No. 64354.
3b. (X6.) Two small ventral valves with very little distortion.
U. S. National Museum, Catalogue No. 64355.
The specimens represented by figs. 3, 3a-b are from siliceous shales
of the Mount Whyte formation (61c) on Mount Odaray, British
Columbia.

Acrothele clitus. Walcottsc.c... csi sew once ces dae bee dale ee eee eee
Fic. 4. (<6.) An exfoliated and crushed ventral valve. U. S.
National Museum, Catalogue No. 64356.
4a. (X6.) A crushed ventral valve with the shell preserved.
U. S. National Museum, Catalogue No. 64357.
4b. (6.) Cast in the shale of the interior of a dorsal valve.
U. S. National Museum, Catalogue No. 64358.
4c. (6.) Interior of a dorsal valve. (On same piece as 4b.)
U. S. National Museum, Catalogue No. 64350.
The specimens represented by figs. 4, 4a-c are from the fine sili-
ceous Lake Agnes shale (35e) of the Mount Whyte formation,
above the head of Lake Agnes, Alberta.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

LOWER CAMBRIAN TRILOBITES AND BRACHIOPODS

NOLS FAUNA OF THE MOUNT WHYTE FORMATION TOQ

MI ERIICN te CORMIES. VVAICOtGs utes a itacign els scarce bods gow sle Sl ecd seb ed ote. 70
Fics. 5, 5a. (X1.5.) Top and side view of a ventral valve from
which the outer shell is exfoliated. U.S. National Museum,
Catalogue No. 64360.
5b. (X15.) Cast of the interior of a ventral valve showing traces
of the great vascular sinuses. U. S. National Museum,
Catalogue No. 64361.
5c. (>< 41.5.) Cast of the exterior. of a- dorsal valve. U.S.
National Museum, Catalogue No. 64362.

The specimens represented by figs. 5, 5a-c are from oolitic lime-
stone near the summit of the Mount Whyte formation (63a), east
base of Ptarmigan Peak, Alberta.

OO ASEM CAL OMEN ial COLE acim sree ose ave ecole ore Shel e Ge Nae hd touele tele wee aon 69
Fic. 6. ( 4.) Exfoliated ventral valve. U. S. National Museum,
Catalogue No. 64363.
6a. (X6.) Cast of interior of a ventral valve. U. S. National
Museum, Catalogue No. 64364.
The specimens represented by figs. 6, 6a are from locality 63g,
Lower Cambrian: Mount Whyte formation; greenish arenaceous
shale, southwest slope of Mount Temple, Alberta.

110 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 11

Crepicephalus ceciina Walectt. 200.5 2. Lun Sones Sanne ean ee ee 99
Fig. 1. (X4.) A broken cranidium, the type of the species showing

the tuberculated surface. U. S. National Museum, Cata-
logue No. 64365.

1a. (X4.) Pygidium associated on the same piece of limestone
with the cranidium represented by fig. 1. U. S. National
Museum, Catalogue No. 64366.

1b. (X4.) Side outline of the pygidium represented by fig. Ia.

The specimens represented by figs. I, 1a-b are from locality 63a,
Lower Cambrian: Mount Whyte formation; Ptarmigan Peak,
Alberta.

Crepicaphalus celer ~W alcott « \si0/.\c%. (ai sis)s's's 210 0 lntarsoateraetb la te 2 Otele eieiona ee IOI
Fic. 2. (XX 1.5.) View of the type specimen of the pygidium, which is
slightly distorted. U. S. National Museum, Catalogue
No. 64367.
From locality 58k, Lower Cambrian: Mount Whyte formation;
Mount Stephen, British Columbia.

Piychoparnia clusia® Waleottss.c.426 0c oe coe enee sce tee one eee eee 85
Fics. 3, 3a. (3.) Top view and side outline of the type cranidium
of the species. U. S. National Museum, Catalogue No.
64368.

From locality 58k, Lower Cambrian: Mount Whyte formation;
Mount Stephen, British Columbia. |

Piychoparia cuneas: Walcott. 110.6) .5 an. s eae le ates sete eee 87
Fics. 4, 4a. (> 3.) Top and side view of the type cranidium of the
species. U.S. National Museum, Catalogue No. 64369.
From locality 35f, Lower Cambrian: Mount Whyte formation;
Mount Stephen, British Columbia.

Piychoparia cossus Walcott .52 0.2.0... = divas Salis se eee eee 86°
Fics. 5, 5a. (X3.) Top view and side outline of the type specimen
of the cranidium. U.S. National Museum, Catalogue No.
64370.

From locality 61a, Lower Cambrian: Mount Whyte formation;
gray oolitic siliceous limestone, Yoho Canyon, British Columbia.

Oleno pss \crata Walcott <5 siiitec: on cite «eines ters scorer eels tains eee eee 75
Fic. 6. (Natural size.) The type specimen of a large cranidium,
which has been partially restored on the right side. U. S.
National Museum, Catalogue No. 64371. ;
6a. (Natural size.) Interior of free cheek associated with the
cranidium represented by fig. 6. U.S. National Museum,
Catalogue No. 64372.

NO. 3, PL,

VOL. 87.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

LOWER CAMBRIAN TRILOBITES AND PHYLLOPOD

NO <3 FAUNA OF THE MOUNT WHYTE FORMATION

II!

Olenopsis crito Walcott—Continued. PAGE

6b. (Natural size.) A small broken cranidium associated in the
same layer of -shaly calcareo-arenaceous sandstone with
the specimen represented by fig. 6. U.S. National Museum,
Catalogue No. 64373.
The specimens represented by figs. 6, 6a-b are from locality 60e,
Lower Cambrian: Mount’ Whyte formation; Ptarmigan Lake Pass,
Alberta.

Dorypge damia: Walcott............. Ly Seer res bl Od Pa a ee
Fic. 7.. ( 1.5.) . Fragment of a cranidium and pygidium on a small
piece of limestone. U. S. National Museum, Catalogue
No. 64374.
7a. (X41.5.) Pygidium associated with the cranidium represented
on fig. 7. U.S. National Museum, Catalogue No. 64375.
The specimens represented by figs. 7, 7a are from locality 62w,
Lower Cambrian: Mount Whyte formation; oolitic limestone, ridge
above Gog Lake, British Columbia.

DR ETAL USTL WVIAC OPE SR re ce oe Nac oe ane eee ce od aisle ware ois Seem eltis
Fic. 8. (X6.) View looking directly down on the type specimen of
the carapace from above. U. S. National Museum, Cata-
logue No. 64376.
8a. (X<6.) Side view of the carapace illustrated by fig. 8.
- From locality'61d, Lower Cambrian: Mount Whyte formation;

- oolitic limestone, southwest slope of Mount Shaffer, British Colum-
bia.

102

II2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 12

Piychoparta ?°cercops Wealcott...c0 35 co. srctedace ane peeeiee ee eee 81
Fic. 1. (Natural size.) A broken cranidium from which the test has
been exfoliated. U. S. National Museum, Catalogue No.
64377.
1a. (X4.) A small cranidium associated with the specimen
represented by fig. 1. This may be taken as the type cranidi-
um of the species. U.S. National Museum, Catalogue No.
64378.
1b. (X3.) Free cheek, broken from the same piece of limestone
as the specimen represented by fig. 1a. U. S. National
Museum, Catalogue No. 64370.
Ic. (X4.) Fragment of a thoracic segment associated with
cranidia of this species. U.S. National Museum, Catalogue ©
No. 64380.
1d. (X4.) Pygidium broken from the same piece of rock con-
taining the cranidium illustrated by fig. 1a. U.S. National
Museum, Catalogue No. 64381.
The specimens represented by figs. 1, 1a-d are from locality 63c,
Lower Cambrian: Mount Whyte formation; Ptarmigan Peak.

Ptychoparia? cleadas’ Walcott. «\sscccnceks tems ts eee ecet anes Pr eo 83
Fic. 2. (X6.) Type cranidium of the species. U. S. National
Museum, Catalogue No. 64382.
From locality 57s, Lower Cambrian: Mount Whyte formation;
mear the base of the gray oolitic limestone, on Mount Bosworth,
British Columbia.

Ptychoparta.adina Walcott... sf.cen 5 eb oa Gaee waele tee ee ee 78
Fic. 3. (X6.) Type cranidium of the species. U. S. National
Museum, Catalogue No. 64383.
3a. (X6.) A free cheek occurring on the same piece of limestone
with the cranidium represented by fig. 3. U. S. National
Museum, Catalogue No. 64384.
3b. (X3.) A small pygidium broken from the piece of limestone
containing the cranidium represented by fig. 3. U. S.
National Museum, Catalogue No. 64385.
The specimens represented by figs. 3, 3a-b are from locality 57q,
Lower Cambrian: Mount Whyte formation; drift block on the
south slope of Mount Bosworth.

Piychoparia gogenses Walcott: << oi iaitsess vases ve oboe eae coe oe 88
Fics. 4, 4a. (X2.) Top and side view of the type cranidium of the
species. U.S. National Museum, Catalogue No. 64386.
From locality 62w, Lower Cambrian: Mount Whyte formation;
above Gog Lake, Wonder Pass.

67, NO. 3, PL.

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

LOWER CAMBRIAN TRILOBITES

“ . =

IE OF Mae = eee,” een eee Oe ee, ey eka ee

NOs 3 FAUNA OF THE MOUNT WHYTE FORMATION I1t3

MIT IAEA OE, NV UIC OT aso 6G cic Se storia ese a tnisatsrel tae S oR OD case Beate 90
Fic. 5. (X4.) The type cranidium of the species. . U. S..National
Museum, Catalogue No. 64387..
From locality 61d, Lower Cambrian: Mount Whyte formation;
southwest slope of Mount Shaffer.

RECUR HOVGRNE LAtG VW OLCOtt aL... <r sac « soc vend eee ota als ale bees Ea tapa a Sea ake 96
Fic. 6. (xX 3.) Type cranidium of the species. U. S. National
Museum, Catalogue No. 64388.
From locality 35h, Lower Cambrian: Limestone of Mount Whyte
formation ; Mount Bosworth.

PMH PAL PEPIN ALGAE fz. a ancis sous op wince dwiaya'e oat 4iSate a oldies cee aioe aolek ee gI
Fic. 7, (X2.) Photograph of a cast made from a dorsal shield that
was somewhat flattened in the shale. U. S. National
Museum, Catalogue No. 64380.
7a. (X2.) Acranidium preserving some of its original convexity.
Note the median longitudinal ridge on the glabella. U. S.
National Museum, Catalogue No. 64390.
The specimens represented by figs. 7, 7a are from locality 35m,
Lower Cambrian: Mount Whyte formation; Lake Agnes shale,
above Lake Agnes.

Ptychoparia pia Walcott....... HAAR Satan ki tama Va tegen Geyer 93
Fic. 8. (X3.) Top view of the type specimen of the cranidium.
U. S. National Museum, Catalogue No. 64391.
From locality 35f, Lower Cambrian: Mount Whyte formation;
Mount Stephen.

PeEVCHOPALIG. SKAPEG > WACO. oi .icens cx cde enans Ris AUS Soe eae Lote 95
Fics. 9, 9a. (X 3.) Top view and side outline of the type specimen of
the cranidium. U. S. National Museum, Catalogue No.
64302.
From locality 62w, Lower Cambrian: Mount Whyte formation;
above Gog Lake.

REC PA CLCTIAY WN AICOLE Se venice Brats vecrecs aid ite Men ER iw ee bho wee ben v's 84
Fic, 10. (xX 5.) Top view of the type specimen of the cranidium.
U.S. National Museum, Catalogue No. 64393.
From locality 35f, Lower Cambrian: Mount Whyte formation;
Mount Stephen.

II4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 13

Agraulos.? .unca, Walcott. 2.22... cusses swnnne ansehen oe =< alee ale ele gainte

Fics. 1, ta. (X4.) Top view and side outline of the type specimen of

cranidium. U.S. National Museum, Catalogue No. 64304.

From locality 6rd, Lower Cambrian: Mount Whyte formation ;
southwest slope of Mount Shaffer.

Agraulos charops Walcott........0..cccccecces nce cence negee ses snas

Fics. 2, 2a. (X4.) Top view and side outline of type specimen of

cranidium. U. S. National Museum, Catalogue No. 64395.

From locality 35f, Lower Cambrian: Mount Whyte formation;

bluish-black and gray limestone, north shoulder of Mount Stephen,
British Columbia.

Olenopsts. cleora. Walcott. «0. 0.00. occ sinc cre 0s oc sccliiere luisa, clsisintells Seta
Fics. 3, 3a. (X1.5.). Top view and side outline of type specimen of
cranidium. U.S. National Museum, Catalogue No. 64396.
From locality 62w, Lower Cambrian: Mount Whyte formation;

oolitic limestone, above Gog Lake, Wonder Pass.

Olenopsis leuka Walcott.:. » &- <i 0 osc. 5ae.0ee ojo: tia oe Bids «hire he oe ee
Fic. 4. (X3.) Top view of the type specimen of cranidium. U. S.
National Museum, Catalogue No. 64397.
From locality 58g, Lower Cambrian: Mount Whyte formation ;
south slope of Mount Bosworth.

Olenopsis ?- agnesensts: Waleott.c. 2. occ. ce bos bes wecis ets vate em eee
Fic. 5. (2.) A nearly entire dorsal shield with the free cheeks re-
stored from another specimen. This is the type specimen
of the species. A poor photograph of this specimen was
reproduced on fig. 2, pl. 36, Smithsonian Misc. Coll., Vol.,57,
1912. U.S. National Museum, Catalogue No. 58364.
From locality 35m, Lower Cambrian: Mount Whyte formation ;
Lake Agnes shale, above Lake Agnes.
Fics. 5a, 5b. (X4.) Top view and side outline of a cranidium from
limestone identified with this species. U. S. National
Museum, Catalogue No. 64308.
5c. (X4.) Fragment of a thoracic segment, associated with fig.
5a. U.S. National Museum, Catalogue No. 64390.
The specimens represented by figs. 5a-c are from locality 58k,
Lower Cambrian: Mount Whyte formation; limestone on north
shoulder of Mount Stephen.

Ptychoparia carina Walcott......... ale cp/a.sle's 60 o\slajaNine'ere pias taal
Fic. 6. (Natural size.) Top view of the type specimen of cranidium.
U. S. National Museum, Catalogue No. 64400.
6a. (X8.) Enlargement of the surface of the anterior portion of
the specimen represented by fig. 6.
From locality 35m, Lower Cambrian: Mount Whyte formation;
Lake Agnes shale, above Lake Agnes.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

LOWER CAMBRIAN TRILOBITES

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 4

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

IV
No. 4.—APPENDAGES OF TRILOBITES

(WITH PLaTEs 14 TO 42)

BY
CHARLES D. WALCOTT

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SAIN
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(PUBLICATION 2523)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
DECEMBER 1918

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The Lord Baltimore Press

BALTIMORE, MD., U. 8. A.

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CAMBRIAN GEOLOGY AND PALEONTOLOGY

IV
No. 4—APPENDAGES OF TRILOBITES

By CHARLES D. WALCOTT
(WitTH PLATES 14 TO 42)

.CONTENTS PAGE

ETN oh ee a ee Rt ie ee ame A ee Be 116

NTE EOS SSS: See ce A 118

SIME OU CN ETITIE SG. 5 o'c-as cs ERP ad Sos ahel ee davis DO poe Dd boo cst een 118
SECTION I

mres OM Species With APPeENdaGES. ss i2c isc ck ccncdssehescedaccccceue. 119

MNERGS 7 OECULECHER: ois EE Aes cea oak sees chide shee sce tenene, 119

PASEO. PECEEUVAUIOM tries sb). 5 ouiacloal tad oh's Sec c bc dleeae 121

DARE TNE a IER. cre idaicss SOMMER IO GT Sis J fae vides ik Sass ds v's oe Nes « 123

MNieeted: Gt OLGPTeSsiGtia ss ssn cc ak eke is hoc Hee oc vce wose 124

MOOR roe tata a os MRD reia sorters <a ted Vece x oiste = « » Phtiocis 42 125

BVETEUSE FAMO OMCHCOMM Mt 1 oes oka veer eee eae codes 125

Description of species with appendages.............. ater ysl of 126

NEGIEMUS SERIRIGS., CROMINGER ) org oie ok aces bate ee cee cadeee Je 126

Oe eitihie (APP EOGADES meta t69 ci Livin Citi videpds « clo e.slseh ng a ecde: 127

PIV CU PADD EHUACCSEM tn oct ainle a k8 fc. sinidial side Ales eaee em nant, 128

ORAM UBO GEUSOTES (CVV AICOLE Ie > oro sic bc ce x <.c. bc suc es’owe coc cd 131

PPSATIM ire EMU IMCISCED, csc pattern Secs sds cle c sss ee tee ees cables ccee es 132

RCCIUS WL RIIES DICICE . JOR (aisle cpolcis stiles cle bee ka vs Obes eden less 133

Isotelus covingionensis Ulrich ? MSS... 0.60.00. ccc cee bccedecece 134

Dee CROC RIONGTOCH). . Peete on cinta tae ays k.eloee aatevais bre nn Sa acdae 135

Bree GUE Tig a) oasis aM Mica eines Wess ySbjeboceiervied etd C50 143

Ptychoparia cordsilere (Rominger).................0cccececeeeee 144

itycnaparia permulias Tew. SPeCieS sve). .c. cs ssaacee de? oecccecncas 145

Walunene Sena GODEAC oes foo ttoe cat oye ee ee eka ee tee elle 147

Ceraurus pleurexanthemus Green.................0 000. bbs Suaness 5 148

RST aT 25 es eee! eee ee a Ok 149

SNS OELG SAITINLIS. crn hs a erad (hath outs hts «oid Oa Shae Sido cow 150

Gdonropleura ivéntonensis CHAU) 6.6 i... os addiccieinc o0s'e 5000 ie bee 153

TMACIOUS CONCENIVICUS FALOGie si 0). s500 ce dacevdsccccecac thins ee 153

CNT AERNISTACCAN) MO oo. 2 aGite vin siscc,erin oe ace eas os anes dsin eae ops 154

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 4

116 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

SECTION 2
Structure of the -trilobite. 5.7% c.<5 «00s wid eraw ce wane oelane ce weiss 154
Dorsal shel: 5 sic scene's vis-00 c10-e.0 s/alaseyrsoncesnte 3 oe arco oe ean 154
Ventral intesuiment 0.5). 605402. cin waco wulee prem cee eee eee 155
Intestinalicanall ..o. sco. os ewecc a tlceiceseoenecees cee ote ee 156
Appendages 5-2 55h elles § o Weleleidls Sale Seiten sicm eislerelonste Sea eee 158
ttm is via 5 21s: sviiw ayes dieie a aia ofadvetnla’ee eaiey on Se ate thee 158
Cephalic. 3 igvis.s:s Sitosiaice aoe ce 0G bs cate eee 160
THOVaeIe (otic sten ere niat eae oe eM as 3h crm see) oe 160
Py@idial. 2. isdn cedla'e ¢ bulge bens os.d facie pee eee 161
Semama;y eo ccs ie ake ine oieras sm, s'o 4,5 picieleie siete eer 161
Position of the limbs... 2.0.6. <0... 6 ses eae oe 162
Respiration of the trilobite: .2% cc.) ode. ss acess a seen 164
Restoration of ventral appendages, 2% 2c). <1. om cniicselatelelcior eterna 165
Restoration of thoracic limbs. . 2. i-c<:. d0.04.+ = «s/s cnr eile 166
Comparison ‘with crustaceans... 2:00 siseias + s.cu1se > Wisin = ee 167
Tracks and trails of trilobites. . 0.2 «0:0 sic 0.00 ess 9 ote er 174
Tn ests cases dvieiet secevsoveow la. a:ae ee 5,0 ye ee Woniaitin ls, cate w/e sista: Staaten 217
ILLUSTRATIONS
Plates TA-AB edo os as Sa dc 0c alesis «nied siviae aiclwhpetes serrate etna tenn 180-216
Text Tess. 1952 3%. cts sclera Siete: e's vatats a tare @ chav ciahe, dhe oie-6 acy evesrheeal pene en 72
INTRODUCTION

In September, 1873, I said to Professor Louis Agassiz that if
opportunity offered I would undertake as one bit of future research
work to determine the structure of the trilobite. This promise has
kept me at the problem for the past forty-five years, and except for
the demands of administrative duties the investigations would have
been advanced much more rapidly. .

Since 1873 I have examined and studied all the trilobites that were
available for evidence bearing on their structure and organization.
The first summary of results was published in 1881 * and a restoration
and cross-sections given of the ventral surface of Calymene senaria
(loc. cit., pl. VI) based on sections cut through the test, ventral cavity
and appendages. These proved that the trilobite had a pair of
biramous appendages for each segment of the thorax and abdomen
and four pairs of cephalic appendages, the enlarged proximal joints
of which served as organs of manducation. The restorations have
since been shown to be essentially correct with the possible exception
of the enlargement of the terminal joints of the posterior cephalic

1The Trilobite: New and Old Evidence Relating to its Organization. Bull.
Mus. Comp. Zool., Cambridge, Mass., Vol. VIII, No. 10, 1881, pp. 191-224,
pls. I-VI.

aNO:- 4 APPENDAGES OF TRILOBITES D7

legs and the too short, proximal joints (protopodites). The placing
of the Trilobita under the Class Peecilopoda in 1881 was changed in
1894* when it was suggested that the Trilobita, Entomostraca, and
Malacostraca were descendent from a common ancestor of pre-
Cambrian time. In 1912* the Trilobita were represented as descen-
dent from the Branchiopoda and on the line of descent of the Mero-
stomata. The presence of antennules was not known positively until
Valiant discovered antennules on Triarthrus* in 1892, and caudal
rami until Walcott found them on Neolenus twenty years later."

During the field seasons of 1910 to 1913 and 1917 I collected from
the Burgess shale member of the Middle Cambrian Stephen forma-
tion of British Columbia with the aid of assistants a large fauna
including specimens of the highly organized trilobite Neolenus
serratus, some of which have beautifully preserved ventral appen-
dages. Neolenus has a large head and tail, a short compact thorax,
and is far advanced in the development of the Trilobita. Always
hoping for more perfect specimens, a detailed description with illus-
trations was deferred, and only a few of the best specimens photo-
graphed and incidentally used in illustrations.. More data are
desired, but I have decided to now record the evidence at hand as the
Burgess shale quarry on the ridge connecting Mounts Wapta and
Field is about exhausted and only a new locality or a chance specimen
in the debris from the quarry will give further material from there
for study.

For a description of the Burgess shale and the mode of occurrence
of fossils the reader is referred to notes published in 1912.° In this
paper I stated that [p. 192]

In the near future I wish to review the conclusions published in my paper
of 1881,’ and those that have been entertained regarding Triarthrus becki and
the new material from the Burgess shale.

As it is not probable that I shall again write on the structure of the
trilobite I am now assembling in this paper notes and illustrations on
the material studied from time to time since 1894. This includes the

* Proc. Biol. Soc. Washington, Vol. IX, p. 94.

? Smithsonian Misc. Coll., Vol. 57, p. 164.

> The Mineral Collector, New York, Vol. 8, No. 7, 1901, pp. 105-112.

“Smithsonian Misc. Coll., Vol. 57, 1912, p. 208, pl. 24, figs. 1, Ia.

> Idem, 1911, pl. 6, figs. 1, 2; 1912, pl. 24, figs. 1, 1a; pl. 45, figs. I, 2, 3, 4.

Text-book Pal. (Zittel), Eastman 2d ed., 1913, Vol. I, p. 701, fig. 1343, p. 716,
figs. 1376, 1377.

* Smithsonian Misc. Coll., Vol. 57, pp. 149-153.

*The Trilobite, New and Old Evidence relating to its Organization. Bull.
Mus. Comp. Zool., Harvard Coll., Vol. VIII, 1881, pp. 208-211.

118 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

specimens of the Cambrian genera Neolenus, Kootenia, and Ptycho-
paria and the Ordovician genera Calymene, Ceraurus, Isotelus, and
Triarthrus.’ Of these, Neolenus has given the best and most instruc-
tive material of a trilobite in advanced development, and Triarthrus
of a more primitive form.

The discussion of the appendages found in the several genera
follows the description of the material known to me of each of the
genera mentioned.

In a memoir soon to go to press by Dr. Percy E. Raymond I under-
stand there will be a very complete statement of Beecher’s work and
a full review of what is known of the trilobite.

ACKNOWLEDGMENTS

I am indebted to the Museum of Comparative Zoology, Harvard
University, for the opportunity of studying the Walcott collection
of Calymene senaria and Ceraurus pleurexanthemus showing appen-
dages. To the Peabody Museum, Yale University, for the loan of a
portion of the Beecher collection of Triarthrus beckt. To several
assistants in the field collecting at Burgess Pass, notably Dr. Lan-
caster D. Burling, now of the Geological Survey, Canada. Mr. R. D.
Mesler, of the U. S. National Museum, and to the members of my
family who worked with me during several field seasons. In the
office, Mr. Clarence R. Shoemaker, of the U. S. National Museum,
made-the final drawings of the restorations of the ventral surface of
Neolenus, Calymene, and Triarthrus, using his knowledge of the
crustacea to give a less diagrammatic appearance to my outline -
sketches. Mrs. Mary V. Walcott retouched the photographs used in
illustration on plates 14, 18, 19, 20, 22, and 23. Miss G. R. Brigham,
Ph. D., lettered the plates and read the text-proofs.

CORRECTION

In 1911 I referred figures 2 and 3, plate 2, also text figure 10, p. 206
(1912), of Emeraldella brocki to Sidneyia inexpectans in the paper
on the latter species.” At the time I had not thoroughly studied
E. brocki, and assumed that the specimens before me belonged to
Sidneyia. In both cases the reference should be to Emeraldella, I
expect in the near future to revise my preliminary work on the
crustaceans from the Burgess shale.

* Through the courtesy of the Museum of Comparative Zoology, Harvard
College.

* Through the courtesy of the Peabody Museum, Yale University, and the
U. S. National Museum.

* Smithsonian Misc. Coll., Vol. 57, rort.

NO. 4.., : APPENDAGES OF TRILOBITES I19g

SECTION 1
NOTES ON SPECIES WITH APPENDAGES

Mobe or OccuRRENCE*

The two species of Ordovician Trilobites, Calymene senaria and
Ceraurus pleurexanthemus, from which nine-tenths of the sections
illustrating appendages were obtained, are the two most abundant
forms in the Trenton limestone of Central and Northern New York.
Their remains, or those of representative species, occur, usually in a
fragmentary condition, in nearly every layer of the Trenton lime-
stone, and range, above, into the Cincinnatian and, below, into the
Black River limestone. Their geographic distribution is also great,
as they occur in the Eastern Canadas and at nearly all the exposures
of the Trenton series in the Northern United States, as far west as
the Mississippi River. Calymene is much more abundant in Ohio,
but at the locality from which the specimens of Ceraurus preserving
appendages were obtained, the latter far exceeded it in numbers.
The special interest attached to the occurrence of both species near
Trenton Falls, Oneida County, New York, as well as of several other
species, is their very perfect state of preservation in a thin layer of
limestone outcropping in a small ravine half a mile east of the
Trenton Falls canyon or gorge in the Township of Russia, Herkimer
County, New York. An examination of the same horizon that this
bed occupies, for several miles along the canyon, which is but half
a mile away at one point, failed to give a single entire trilobite, and
the fragmentary remains are rare. They are found both above and
below the prolific layer of limestone, but not with any more of the
animal preserved other than the dorsal shell and hypostoma. This
indicates that in the vicinity of the outcrop in the small ravine there
is a limited area, which was surrounded by conditions in Ordovician
time that did not prevail elsewhere in the region, as the topography
of the adjacent country permits of a close examination of the strata,
and outcrops at about the same horizon were examined in all direc-
tions in the vicinity for the purpose of finding appendage-bearing
trilobites.

*Walcott, C. D.: The Trilobite: New and Old Evidence relating to its
Organization. Bull. Museum Comp. Zool., Harvard Coll., Vol. VIII, 1881,
No. 10, pp. 211-214.

120 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The layer of limestone on which the prolific layer rests is about
ten inches thick, and formed of the comminuted remains of crinoids,
trilobites, etc., indicating the action of shore waves and a distributing
current. A change supervened, and this surface was depressed
beneath deeper water, or a barrier reef was formed, affording a quiet
habitat in which flourished bryozoans, echinoderms, brachiopods,
pteropods, entomostracans, and trilobites. The remains of all these
are now found in a fine state of preservation attached to the lower
surface of the superjacent layer of limestone which appears to have
been a fine calcareous mud or ooze, deposited rapidly on the surface
of the subjacent stratum, so as to form when solidified a Jayer from
one-half to two inches in thickness. It did not destroy all the forms
of life that existed on the surface prior to its deposition, but many
species are not known to occur above it. The trilobites, however,
flourished on the new upper surface as the beautifully preserved
interiors of the dorsal shell testify, an illustration of which is given
on plate 28.

Where the layer is over one inch in thickness, and there is no
intermingled argillaceous shaly matter, as sometimes occurs, the best
preserved specimens for cutting sections are found. They are
usually with the dorsal surface downward, and partially enrolled.
It was frequently noticed in polishing the sections that the imbedding
rock showed dark laminations curving beneath the trilobite, as
though the soft mud had been compressed by its sinking down into
it. Similar traces proved that the mud flowed over into the half-
enrolled shell, but buried the appendages, or such as were left of
them, as often the laminations of the inflowing mud have not been
disturbed since covering the viscera and fragments of the branchiz
and limbs.

In a former paper’ it is stated that 1,110 trilobites out of a total
of 1,160 had been found resting on their backs, and it was argued
from this that that was their normal position when living, as Bur-
meister had shown for Branchipus and theoretically for the trilobite.
In subsequent work the proportion was found to remain nearly the
same, but with the discovery of ambulatory thoracic legs the view
of their living in that position was necessarily abandoned. Mr. Henry
Hicks writes that he had observed the same position in the Primordial
Trilobites of Wales, the shell of the great Paradoxides, eighteen
inches in length, occurring with its dorsal surface downward. He
attributes it, and I think correctly, to the accumulation of gases in

* Ann. Lyc. Nat. History, Vol. XI, p. 159, 1875.

NO. 4 APPENDAGES OF TRILOBITES I21

the viscera, which, with the boat-shaped shell, would cause the animal
to turn over on the slightest motion in the water, and it would there
remain to be buried beneath the next deposit of sediment.

Beecher calls attention to his finding nearly all of the specimens of
Triarthrus becki with the back down. His explanation of the occur-
rence is as follows:*

It seems most probable that trilobites could both swim freely and crawl
along the bottom, and that, on dying, they coiled themselves up in the same
manner as the recent isopods. Then upon unrolling they would necessarily
lie on their backs. Even if they did not coil up, any swimming animal having
a boat-shaped form would settle downward through the water with the con-
cave side up.

The specimens of Neolenus from the Burgess shale were obtained
from blocks of shale after they had been blasted from the quarry,
and there is no record of their position. In one case illustrated on
plate 15, one specimen was ventral side up and the other showed the
dorsal side. The appendages are about equally well preserved and
do not show the bending under the edge of the dorsal shield, as sug-
gested by Beecher in event of a trilobite being turned over after
settling to the surface of the mud on the bottom of the body of water
in which it was living."

From the great abundance of trilobite tracks on shales and sand-
stones, and from the nature of their food, it is quite probable that
they usually moved about with their dorsal shield uppermost, and
turned over after death. |

CONDITIONS OF PRESERVATION

Trilobites preserving ventral appendages have been found in lime-
stones and both argillaceous and siliceous shale. The specimen of
Isotelus from the Trenton limestone at Ottawa, Canada, was found
about 1860 in a thin slab of typical dark bluish-gray compact lime-
stone. The animal had evidently settled in the calcareous mud with-
out any considerable disturbance of its legs (endopodites) as the
protopodites of the anterior three pairs of thoracic legs are now at
nearly right angles to the median axis; the posterior legs are sloping
backward as in the Ohio Jsotelus (pls. 24, 25). From the fact that
the legs occur near the under surface of the dorsal shield it is prob-
able that the animal settled in the mud with the ventral surface up and
that the accumulating sediment crowded the legs down into the con-
cave shield and displaced them more or less, but did not tear them

* American Geologist, Vol. XIII, 1894, p. 40.

I22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

from their fastenings to the ventral surface. The appendages are
preserved as limestone replacements of the original parts.

The Ohio Jsotelus (pl. 24, fig. 3; pl. 25, fig. 1) also occurs in a
fine-grained, compact limestone, and it shows the effect of compres-
sion in the sediment by the backward slope of the proximal joints
(protopodites) of the legs. In both specimens mentioned the em-
bedding mud was relatively soft and the animal must have been
quickly covered over. The limbs are preserved as a limestone
replacement of the original limbs, the integument having disappeared.

The specimens of /sotelus from the Trenton limestone, near Tren-
ton Falls, New York, preserving traces of the thoracic limbs, occur
in a compact, hard, bluish-gray limestone that was formed from a
relatively soft, calcareous mud into which the animal readily sank
and became embedded.

The specimens of Calymene and Ceraurus with ventral appen-
dages preserved are from a thin layer of compact, fine-grained, bluish-
gray limestone which was originally a relatively soft calcareous sedi-
ment that quickly covered the trilobites on the bottom or in some
instances they sank into the mud and were buried without material
disturbance of the appendages. The integument of the limbs and all
parts have often been replaced by calcite, which makes it possible to
obtain sections showing the outlines of the appendages in the dark
limestone matrix.

Triarthrus with appendages occurs in a black, compact thin band
of argillaceous shale and the appendages and often the dorsal shield
are preserved by being replaced by iron pyrite. I have found
hundreds of specimens of 7. becki in other localities than that near
Rome, New York, but none showed traces of appendages. Local
conditions were favorable for their preservation in the thin band of
shale near Rome just as they were favorable for those found in the
Middle Cambrian Burgess shale.

The Burgess shale trilobites Neolenus, Kootenia, and Ptychoparia
occur in a band of fine siliceous shale about one meter in thickness
in which the appendages are preserved as a black, almost glistening,
carbonaceous appearing substance that is not readily attacked by
acids. The siliceous shale of the layers containing the trilobites
with appendages is remarkably uniform throughout and it was evi-
dently a fine, rapidly deposited silt. “‘ That carbonic acid gas was
present in the mud and immediately adjoining water is suggested by
the very perfect state of preservation of the numerous and varied
forms of life. These latter certainly would have been destroyed by

NO. 4 APPENDAGES OF TRILOBITES 123

the worms and predatory crustaceans that were associated with them,
if the animals that dropped to the bottom on the mud or that crawled
or were drifted onto it were not at once killed and preserved with
little or no decomposition or mechanical destruction. This conclu-
sion applies to nearly all parts of a limited deposit about six feet in
thickness, and especially to the lower two feet of it.”* The fact that
there are few trilobites found in the deposit and that their frag-
mentary remains are unusually abundant in the rocks beneath indi-
cates that those found with appendages were individuals that strayed
in from more favorable surrounding areas.

MANNER oF LiFe?

Burmeister gives us, as his view of the manner of life the trilobites
led, “ that they most probably did not inhabit the open sea, but the
vicinity of coasts, in shallow water, and that they here lived gre-
gariously in vast numbers, chiefly of one species; that they moved
only by swimming in an inverted position, and did not creep about
on the bottom; that they lived on smaller water animals, and, in the
absence of such, on the spawn of allied species.”

Barrande supposed that they lived in deep water and swam on the
surface of the sea.

Dr. Dohrn considers that they lived at the bottom of the sea, and
with extremities like those of Limulus crawled about. This view
was necessarily taken by all authors who considered the trilobite as
related by its zodlogical affinities to Limulus.

Dr. Packard states * that Mr. Alexander Agassiz had captured the
larva of Limulus swimming free on the surface of the ocean, three
miles from the shore. From the comparisons made by Dr. Packard
between the young Limulus and the young trilobites as described by
M. Barrande, there is no reason to doubt that the young trilobite may
have had the same power of distributing itself and its species over
extended areas in the wide-spread paleozoic seas. As in Limulus its
later growth changed its manner of life, and its movements were
finally largely restricted to crawling about the sea bottom in search
of food.

1 Smithsonian Misc. Coll., Vol. 57, 1911, No. 3, p. 42.

? Walcott, C. D.: The Trilobite: New and Old Evidence relating to its
Organization. Bull. Museum Comp. Zool., Harvard Coll. Vol. VIII, 1881,
No. 10, pp. 214-215.

®> Development Limulus polyphemus, Memoirs Boston Soc. Nat. Hist., p. 155,
1872.

124 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

We have seen from the views of Burmeister, Barrande, ‘and others,
that it has been thought to be both an inhabitant of shallow waters
along the coasts and also of the deeper seas. It is found in both
littoral and deep-water formations. Muddy or sandy, fine or coarse,
hard or soft, argillaceous or calcareous deposits, it occurs in all.
With these facts in view, it is probable that it ranged along the shore
in quiet bays, and also in the habitat of the brachiopods and other
deeper water invertebrates. In conclusion we may say that the trilo-
bite in its younger stages of growth was active and a free swimmer,
thus distributing itself over broad areas; that on reaching a larger
growth it became more limited in its natatory powers and crawled
about the bottom in search of soft-bodied organisms for food and
during the spawning season for a place to deposit its eggs.” From
the presence of broad setiferous exopodites on the limbs of Neolenus
and Triarthrus, and endopodites (legs) with flattened joints on other
species it is highly probable that the trilobite as we now know it may
have had limited natatory powers, during its adult life, but it prob-
ably swam about in its local habitat, and rarely moved far away after
once finding a favorable environment.

Method of progression.—The strong, long legs of trilobites enable
them to crawl rapidly over the surface of hard or moderately compact
sediments either under water or over the wet surface of the beach
between tides. When searching for worms, their principal source of
food, they evidently worked down into the mud very much as the
horseshoe crab (Limulus) does and by means of their strong pro-
topodites and legs pushed the dorsal shield along, thus forming
deep trails and half burrows, which when made in moderately stiff
clay or arenaceous mud retained the form of the trail and burrows
until the next tide or current filled them up and a natural cast was
formed; these trails and casts occur in great abundance as fossils,
and thus preserved the record of the method of movement of the
trilobite when crawling about and when feeding. Often the deeper
trails appear as though the animal had settled in the mud and then
lifted itself up on the ends of its legs, moved ahead a little, and then
settled down again, repeating the movement for considerable
distances.

Swimming was the method of more rapid progress by some species
when the animal moved any considerable distance, or was avoiding
immediate danger which it could not escape by burrowing or clinging

+See Dr. Packard’s description of the spawning of Limulus and its probable
occurrence in the same manner with the trilobite. Jbid., p. 186.

NO. 4 APPENDAGES OF TRILOBITES 125

to the bottom. Of the species of which we know something of their
limbs, all had a limited development of swimming power either by
using the flat, jointed legs or the exopodites or epipodites. It is not
probable, however, that they were great swimmers with possibly the
exception of Triarthrus.

Food.—The gnathobases of the cephalic limbs of trilobites clearly
indicate that their food was largely worms and such soft bodied and
small, minute life as came in their way, also rotting alge and any
decomposed animal matter.

The habitat of Neolenus abounded in worms, soft invertebrates,
and fine, delicate alge, and in all rocks where I have known entire
trilobites to occur there has been strong evidence that worms and
usually algz were abundant. There is not any evidence that the
trilobite possessed strong manducatory jaws similar to those of the
Eurypterida or the more insignificant branchiopod A pus.

Defense and offence-—The known limbs of the trilobite were with-
out offensive or defensive power. For defense many of them could
enroll, and all could settle down closely on the bottom or burrow in
the mud and thus present only a smooth, hard surface or a spiny
shell to attack. Calymene is frequently found enrolled, the head and
pygidium fitting closely together, so that no opening is left at any
point, the legs being all drawn within the shell and entirely protected
from injury from without. With Ceraurus pleurexanthemus, a per-
fect closing of the shell by enrolment is impossible, and the space
formed by the partial enclosure of the spinous extension of the
pleurz affords but an incomplete protection to the numerous legs and
branchiz." Neolenus and Triarthrus could not have rolled up
effectively as compared with Calymene.

Without offensive or special defensive parts they were evidently
peace-loving and depended on great reproductive power and favor-
able environment for continued existence. In Cambrian time they
were the largest element in the fauna and,had only two known species
of Eurypterida to interfere with them. After this, enemies gradually
increased and the number of species and of individuals decreased
until the race became extinct in early Carboniferous time. Bacteria
undoubtedly existed, but as yet we have no record of their presence
in the trilobite.

*Walcott, C. D.: The Trilobite: New and Old Evidence relating to its
Organization. Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, No. 10,
1881, p. 203.

126 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF SPECIES WITH APPENDAGES
Order OPISTHOPARIA Beecher

Family ORYCTOCEPHALIDZ Beecher
Genus NEOLENUS Matthew
NEOLENUS SERRATUS (Rominger)
PLATES 14-23

Ogygia serrata RoMINGER, 1887, Proc. Acad. Nat. Sci. Philadelphia, p. 13,
pl. 1, figs. 2, 2a. (Description and illustration.)

Neolenus serratus MATTHEW, 1899, Trans. Royal Soc. Canada, 2d ser., Vol. 5,
sec. 4, p. 53. (Mentioned in proposing genus Neolenus.)

Neolenus serratus WAtcottT, 1908, Canadian Alpine Jour., Vol. 1, No. 2, pl. 4,
fig. 3. (Figure of dorsal test.)

Neolenus serratus GRABAU and SHIMER, 1910, North Am. Index Fos., Vol. 2,
p. 271, fig. 1566. (Reproduces Walcott figure.)

Neolenus serratus Watcott, 1912, Smithsonian Misc. Coll., Vol. 57, p. 190,
pl. 24, figs. 1, 1a. (Figures specimens showing appendages.)

Neolenus serratus EASTMAN, 1913, Text-book Pal. Zittel, 2d ed. by Eastman,
Vol. 1, fig. 1343, p. 701, figs. 1376, 1377, p. 716. (Illustration of ap-
pendages from photographs furnished by Walcott.)

Neolenus serratus Watcott, 1916, Ann. Rept. Smithsonian Inst. for 1915,
1916, pl. 9. (Figured with appendages.)

The dorsal surface of the test or carapace is illustrated by figure 1,
plate 14. The cephalon is formed of seven fused segments or
somites, the thorax of seven free segments, and the pygidium of five
fused segments, a total of 19 segments. The large cephalon and
pygidium and thorax with only seven thoracic segments indicate
an advanced form of trilobite as compared with Ptychoparia, Triar-
thrus, Calymene, and Ceraurus. Neolenus more nearly approaches
Isotelus of the Cincinnati formation in form of its dorsal shield, but
unfortunately only the protopodite and endopodite (leg) are known
of the ventral appendages of Isotelus (pl. 25).

Cephalon of Neolenus—vThe cephalon is formed of seven com-
bined or fused segments. These include:

(a) The ocular or eye-bearing segment represented by the free cheeks;

(b) The palpebral or palpebral ridge-bearing segment which at the center
is merged into the anterior lobe of the glabella.*

(d) The occipital or posterior (neck) segment.

The four posterior segments fused in the glabella are usually
clearly indicated by the glabellar furrows, but owing to compression
of the test in the shale the short, faint anterior pair of lateral furrows

* Smithsonian Misc. Coll.. Vol. 53, 1910, p. 237, last paragraph.

NO. 4 APPENDAGES OF TRILOBITES 127

indicating the division in the anterior lobe of the glabella are to be
seen only in rare specimens that preserve the natural convexity of
the test. The fusing of the segments of the cephalon of the trilobite
is finely shown in the young of the Mesonacide.*

CEPHALIC APPENDAGES

These consist of the antennules and four pairs of cephalic limbs.
The first pair may represent the antenne; the second pair the
mandibles; the third pair the maxillule, and the fourth pair the
maxillz of the theoretical crustacean head.

Antennules—The antennules are long, slender, and formed of
short joints for the first half or more of their length and of longer
segments in the distal portion. A flattened antennule projecting
from beneath a dorsal shield 65 mm. in length has a width of 2 mm.
at base and 13 segments in the first 12 mm. of its length; at 0.75 mm.
in width the segments are I mm. in length. The exact point of
attachment of the antennule is unknown, but from the contour of
the sides of the hypostoma it probably was attached to the ventral
surface near the posterior third of the side of the hypostoma as
shown on plate 31. Its length and flexibility are well shown on
plate 15. Short, fine acicular spines occur at the distal end of the
joints.

' Endopodites.—Several specimens show one or more well-preserved
cephalic limbs. The limb is essentially the same as the thoracic
limb with the large elongate basal joint (protopodite*) modified
slightly for the purpose of aiding in manducation. In two examples
this joint is seen to be narrowed at the proximal end, but owing to the
flattening of the leg by compression its exact form is not preserved
(fig. 1, pl. 16). The protopodite as flattened in the shale expands
slightly midway and the inner margin is slightly rounded so that if
the leg extends obliquely forward its proximal margin may be more
or less parallel to the longitudinal axis of the dorsal shield. On one
specimen rather strong, short spines occur on the inner margin of the
protopodite of the third cephalic leg (pl. 16, fig. 1). The four follow-
ing joints are strong, compact, and very gradually decreasing in size;
the sixth and seventh are more slender and proportionally more
elongate; the distal extremity is formed of a small,-strong, curved

4Smithsonian Misc. Coll., Vol. 53, 1910, pl. 25, figs. 9-13, 19-22, and pl. 36,
figs. 10-15.

* The protopodite is considered to be in all trilobites preserving their limbs
to be formed by the fusion of the coxopodite and basopodite.

128 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

claw and two small spines, which give when they are spread out
a tripartite termination to the leg." Two or more short, fine spines
occur on the margin of the distal end of each joint of the leg.

The four cephalic legs extend well out from beneath the dorsal
shield in several specimens and appear to be essentially similar. As
yet no “ precoxal ” joint has been observed connecting the large, long
protopodite to the ventral surface and it is doubtful if one existed
distinct from the latter. The protopodite appears to have been
strongly attached to the ventral integument of the head, probably by a
narrow connection that extended from the dorsal side of the. joint
directly to a transversely elongate opening in the ventral integument
through which the muscles of the limb passed.

Exopodite—A long, flat, membranaceous lobe with a terminal
joint is fringed on its posterior margin by fine, long, slender, flattened
setze out to the distal joint which has fine, short setz on its posterior
and outer margins; it appears to be attached to the protopodite at its
distal end and extends outward into the space beneath the lateral
extension of the cephalon and above the cephalic legs (pl. 16, fig. 1;
pl. 20, fig. 2; pl. 22, fig. 1; pl. 34, fig. 3). This lobe appears to be
similar to that attached to the protopodite of the thoracic and
abdominal legs. Nothing has been seen of any epipodites such as are
attached to the thoracic and abdominal limbs.

THoRAcIC APPENDAGES

Each of the seven thoracic segments has a pair of limbs formed of
a simple walking or crawling leg (endopodite), a lobe-like jointed
exopodite, and a jointed epipodite. In addition there is a small,
simple epipodite that was probably present on each one of the legs
and a short, broad lobe with fine, short sete along the margin that
may be an exite such as occurs in Anaspides and Koonunga’* (pl. 35).

Endopodite-—Each thoracic leg (endopodite) is formed of a large
elongate proximal joint (protopodite) ; four strong joints each about
1.5 times as long as wide (basopodite, ischiopodite, meropodite and
carpopodite) ; two slender elongate joints (propodite and dactylopo-
dite) and a claw-like, more or less tripartite termination (pls. 17-20).

The protopodite is about 2.5 times as long as wide when flattened
by compression (pl. 18) ; it expands between its distal and proximal
extremities so that the posterior margin (as flattened) has a gentle

Smithsonian Misc. Coll., Vol. 67, No. 5.
* See figs. I, 2, p. 171, this paper.

NO. 4 APPENDAGES OF TRILOBITES 129

curvature from end to end; the proximal and posterior margins are
lined with short, fine spines similar to those on the second joint and
at the distal end of each joint of the leg. The exact method of attach-
ment of the protopodite to the ventral surface is unknown, but from
its form it necessarily was strongly attached to the ventral integu-
ment of the body at a point on its dorsal surface somewhat as the
limb of the living Apus or Limulus is attached. The form of the
protopodite and the presence of a series of sharp, short spines clearly
indicate that it is to be compared with the gnathobase of the branchio-
pod limb. The second joint of the leg is flattened and slightly ex-
panded on the dorsal and narrowed on the ventral side, as are the
third, fourth, and fifth joints; a marked feature is the sudden con-
traction in size of the sixth (propodite) joint which is about one-half
the diameter of the preceding joints; both it and the seventh joint
(dactylopodite) expand slightly from their base to the distal ex-
tremity. The terminal claw is strong, slightly incurved, and with two
spines nearly as long as the claw inserted beside and a little back of it.
A side view of the claw is shown by figure 1, plate 18, and a view of
the claw and spines spread out by figure 3, plate 16.

The protopodite in its natural condition was probably narrow on
its ventral face, a little broader on its dorsal side and deep on its
anterior and posterior sides. A beaded longitudinal line that is
preserved on several specimens (pl. 17, fig. 3; pl. 18, fig. 1) clearly
indicates the edge of the dorsal face, the other edge being the line
along which the joint folded when flattened out by compression.

Exopodite——Of this there are a number of fairly well-preserved
specimens. It is a broad, long, flat plate or lobe of two joints with
many fine, long, flattened sete on its posterior margin so closely
arranged that they are often in the fossil slightly overlapping (pl. 21,
fig. 6) except on the distal joint where the setz are fine and short.
The exopodite appears to have been attached to the protopodite at its
distal end and to have extended outward nearly as far as the jointed
leg (endopodite). The close joint towards its distal end is similar
to that of the large epipodite. The position of the exopodite is
illustrated by figure 3, plate 19; figure 6, plate 21, and figures 1, 2,
plate 23, and in all relatively undistorted specimens it extends
obliquely forward from the side of the axial lobe. Its relation to the
jointed legs (endopodites) is shown by figure 6, plate 21, where the
leg is beneath the exopodite. Figure 1, plate 22, indicates that the
jointed epipodite was between the endopodite and exopodite when
they were pressed down upon each other. From their position and

130 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

form it is probable that the exopodites were used for (a) swimming;
(b) for directing a flow of water over thé gills; and (c) possibly for
directing minute food particles towards the mouth; they may also
have functioned as gills.

Epipodites—The presence of a jointed epipodite was not suspected
prior to the present study, although a few traces of a thin, structure-
less lobe were met with in attempts to uncover a complete lobe-like
exopodite. A fortunate splitting of a small fragment of shale opened
up a crushed trilobite on the left side of which jointed legs were
exposed and above them four finely preserved epipodites. These
were attached to the protopodite toward its distal portion, judging
from their present position in relation to the endopodite (pl. 20,
figs. 3,4). The epipodite is formed of a long, proximal lobe or joint
and a short distal lobe separated from the proximal by a well-defined,
close joint. The test of the epipodite was very tenuous; it has left
only a film on the surface of the shale, but this retains the outline of
the joints, the transverse line of the joint, and the large interior.
There are traces of fine spines or sete on the posterior margins of the
lobe-like joints. The epipodite is beneath the exopodite and above
the endopodite in the specimens where their relations are clearly
shown (pl. 20, figs. 3, 4; pl. 22, fig. 1). The function of the epipodite
was probably that of a gill or branchia. It has not been possible with
the material available for study to determine if there is a small basal
joint uniting the long, flattened joint and the protopodite as in
Anaspides* (pl. 35, figs. I, 2). .

A small, oval, plate-like lobe is definitely shown on one specimen
(fig. 1, pl. 18, right side), which indicates that there is a second and
smaller epipodite that was probably attached to the protopodite; its
proximal end rests on a protopodite, but owing to the crushing down
and flattening of both, it is impossible to detect where the point of
attachment may have been.

Exites—There is still another series of plate-like lobes that it is
difficult to locate. They are broadly oval in outline with fine, short
sete or spines all around the margin except cn the inner side. They
are best shown by figures 3 and 4, plate 20, where the endopodite or
leg appears to be above them. The separate lobes overlap so that the
anterior margin of each passes beneath the lobe in front. They were
probably attached to the inner side of the protopodite somewhat as
the lobes of the protopodite of the first thoracic limb of Anaspides’*
(pl. 35, fig. 2). My first thought was that the lobes were attached

~10On the genus Anaspides. W.T. Calman. Trans. Royal Soc. Edinburgh,
Vol. 38, pt. 4 (No. 23), 1896, p. 791, pl. 2, fig. 12.

NO. 4 APPENDAGES OF TRILOBITES 131

to the ventral integument just beneath the proximal joint owing to
their position along the side of the axis, as shown by figure 3, plate 20,
but this is highly improbable.

Abdominal appendages.—These consist of five pairs of limbs simi-
lar to those of the thorax except that they diminish gradually in
length and size. There are also two caudal rami.

Caudal rami.—The caudal rami are very long, slender, jointed and
with numerous fine spines on the proximal portion and very fine
spines or sete on the distal segments; the segments are numerous
and slightly longer than the diameter of the rami except toward the
distal portion where they are more elongate. The rami are strongly
attached (probably articulated) to the posterior margin of the ventral
membrane (pl. 17, fig. 3) and suggest a sixth pair of abdominal
appendages corresponding to the posterior or anal segment of the
pygidium. This segment is fused so closely with the fifth segment of
the pygidium that it is rarely that a slight transverse depression
outlines it,

Anal aperture—tThe anal aperture is probably beneath the pos-
terior margin and between the caudal rami (pl. 17, fig: 3). This view
is sustained by the fact that in Ceraurus pleurexanthemus the intes-
tine has been traced to the posterior margin of the ventral’integument
of the pygidium.*

Further reference to the appendages of Neolenus will be found
under the discussion of the appendages of the trilobite.

KOOTENIA DAWSONI (Walcott)
Plate 14, figs. 2, 3

Bathyuriscus (Kootenia) dawsoni Watcott, 1888, Proc. U. S. Nat. Museum,
Vol. XI (issued 1889), p. 446. (Describes species.)

Dorypyge Dawsoni MattHew, 1899, Trans. Royal Soc. Canada, 2d ser.,
Vol. V, sec. IV, p. 56, pl. 3, fig. 1. (Describes and illustrates, referring
species to Dorypyge.)

Dorypyge (Kootenia) dawsoni Watcort, 1908, Canadian Alpine Journ.,
Vol. 1, No. 2, pl. 3, fig. 9. (Illustrates a dorsal shield.)

_ This species combines characters of Dorypyge, Olenoides, and
Neolenus. It has the slightly expanded subquadrilateral glabella of
Olenoides and Neolenus with the unfurrowed, fused, pygidial seg-

* Bull. Mus. Comp. Zool., Vol. VIII, 1881, pl. 4, fig. 6.

132 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

ments of Dorypyge. The fringing spines of the pygidium are simi-
lar to those of the two former genera and quite unlike those of
Dorypyge. The glabella of Kootenia differs from that of Dorypyge
in form.’

These characters serve to distinguish the genus Kootemia from
Dorypyge.

Appendages—Many specimens of K. dawsoni were collected from
the Burgess shale, but only one preserved any of the ventral appen-
dages and these were only on one side beneath the pleura (pl. 14,
fig. 2).

The distal joints of several endopodites of the thoracic limbs
appear from beneath the long exopodites which seem to be similar
to those of Neolenus serratus. The proximal section of the endopo-
dite is long, flat and fringed with strong sete; the distal joint has
fine, short sete along the lower margin and is closely united to the
proximal section. From what there is available for comparison it
appears that Kootenia and Neolenus had essentially the same type
of thoracic limb.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen foriation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of
Burgess Pass, above Field, British Columbia, Canada.

Family ASAPHIDZ Burmeister

Subfamily AsapHina Raymond

There is little to add to published data on the appendages of
Tsotelus, the one genus of the Asaphinz preserving remains of jointed
appendages, except in relation to the form of the endopodites. The
specimen described by Billings * proved that /sotelus had a series of
strong, jointed legs, but without the Ohio specimen*® of Jsotelus
maximus it would have been difficult to interpret the structure of
the legs of the Canadian specimen.

Compare fig. 2, pl. 14, with the cranidia of Dorypyge richthofeni Dames
(Research in China, Carnegie Institution, Vol. III, 1913, pl. 8, figs. 1, 1a).

? Quart. Jour. Geol. Soc. London, 1870, Vol. 26, pp. 479-486, pls. 31, 32.

> Science, Vol. 3, 1884, pp. 279-281, figs. I-3.

NO. 4 APPENDAGES OF TRILOBITES 133

ISOTELUS MAXIMUS Locke
Plate 24, figs. 3, 3a; plate 25, fig. 1
Asaphus megistos MicKLEBOROUGH, 1883, Cincinnati Jour. Nat. Hist., Vol. 6,
p. 200, figs. 1-3. (Describes and illustrates specimen with appendages. )

Asaphus megistos Watcortt, 1884, Science, Vol. 3, p. 279, fig. 1. (Illustrates

some specimens used by Mickleborough and gives notes on same.)

Tsotelus maximus Utricu, MSS.

The large cephalon of the dorsal shield of Jsotelus is made up of
fused segments, traces of which are indicated on the exterior surface,
especially of the young. The number of segments is unknown, but it
is probably the same as for Neolenus, where seven segments are indi-
cated. The thorax has eight free segments and a large pygidium
(fig. 2, pl. 24) clearly shows fourteen fused segments. If this inter-
pretation is correct there are twenty-nine segments included in the
dorsal shield of Jsotelus, and there may have been one or two more
not now discernible in the end of the median lobe of the pygidium.

The unique Ohio specimen shows the protopodites of twenty-six
pairs of limbs (pls. 24, 25). Of these nine are situated directly
beneath the eight segments of the thorax; one beneath the posterior
margin of the cephalon, and sixteen beneath the pygidium. That this
was their natural position is not probable as they must have been more
or less displaced when the animal was pressed down by or in the
mud. That the displacement was not destructive is indicated by the
regularity of arrangement of the legs and the approximation of the
inner ends of the protopodites of the limbs. It is also probable that
the protopodites sloped obliquely forward towards the median line
instead of backward as in the specimen. This is spoken of under the
subheading Position of the Limbs, page 162.

The proximal joint (protopodite) (pl. 25) of each leg is large,
elongate, flattened vertically and extends well in towards the median
line as in Neolenus (pl. 31) and Triarthrus (pl. 32). The second
and following five joints appear to be slender and much like those
found in Calymene senaria, but the first four were probably flattened
and the distal ones rounded as in Neolenus (pl. 31) and Triarthrus
(pl. 32). The drawing, plate 25, shows all that is preserved of the
appendages on both the cast and matrix of the specimen (figs. 3, 3a,

pl. 24).

1Dr. E. O. Ulrich has done much work on the genus and species of Jsotelus
and he very kindly permits me to use his illustrations of this and a second
species, J. walcotti, a form from the trilobite quarry near Trenton Falls, New
York, that I discovered about 1870.

134 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The few traces of setze such as might occur on exopodites of the
type of those of Neolenus are not satisfactory proof that such
exopodites existed in Jsotelus, but they strongly suggest that such
was the case.

Formation and locality—Ordovician: Cincinnatian (Richmond) ;
Oxford, Ohio.

ISOTELUS COVINGTONENSIS Ulrich ? MSS.

Asaphus platycephalus Brtuincs, 1870, Quart. Jour. Geol. Soc. London, Vol.
XXVI, pp. 479-486, pls. XXXI, XXXII. (Describes and illustrates
specimen with fragments of thoracic limbs.)

Isotelus latus RAYMOND, 1913, Bull. Victoria Mem. Museum, Vol. I, 1913,
p. 45, pl. V. (Species described and figured.)

Isotelus covingtonensis UtricH MSS., 1918. Dr. E. O. Ulrich identifies the
specimen described by Billings, which was found at Ottawa, Canada,
with his Jsotelus covingtonensis, which occurs at Covington, Kentucky,
also at Montreal, Canada, in the upper portion of the Trenton limestone.

Billings described the legs as follows:*

The legs are arranged in eight pairs, the bases of each pair being situated
exactly under one of the eight segments of the thorax, and at the sides of the
sternal groove.

The legs of the first pair are better-preserved than the others. They curve
forwards and can be traced to a point nearly under the outer edge of the eye,
or, rather, between the eye and the outside of the head. The other seven pairs
follow at the average distance of two and a half lines from each other. The
eight pairs thus occupy about twenty lines of the length of the ventral surface.
This is exactly the length of the thorax, measured on the upperside. This
trilobite has always eight segments in the thorax; and there is thus on the
underside one pair of appendages to each segment. Although some of them
are very imperfect, and the portions that remain are somewhat displaced, with
a little study of the specimen it can be seen that they all curve forwards, and
are thus, most probably, ambulatory rather than natatory legs.

There appear to be several joints in each of these appendages; but the
exact number cannot be made out. On the left side, the first four legs show
very clearly that there are at least two, one at five lines from the side of the
groove, and another about three lines further out. The position of each of
these is indicated by a small protuberance. On the right side the preserved
portions of the legs are longer, and thus indicate a greater number of articula-
tions, although they cannot be distinctly seen. I think that each leg consisted
of at least four or five articulations.

Through the courtesy of Dr. R. G. McConnell, Director of the
Canadian Geological Survey and Deputy Minister of Mines, I have
recently had the opportunity of examining the specimen studied by
Billings. The protopodites of the anterior thoracic limbs have a
length of 11.5 mm.; they are separated along the median line of the

1 Quart. Jour. Geol. Soc. London, Vol. XX VI, 1870, p. 480.

NO. 4 APPENDAGES OF TRILOBITES 135

ventral surface of the thorax by a space of 4 mm. in width, which
with the length of the two protopodites gives a transverse distance
of 27 mm. or nearly the width of the axial lobe of the dorsal shield ;
this indicates that the protopodites were attached to the ventral
surface near their distal end and extended well in over the meso-
sternites of the ventral integument. The original form of the proto-
podites and following joints of the endopodite has been largely lost
through pressure and the deposition of calcareous matter upon them ;
the distal end of the protopodite is enlarged and all the joints of the
endopodite preserved appear to have been filled with sediment before
the matrix about them was consolidated. There is nothing to indi-
cate that they differed materially from the limbs of [sotelus maximus
(pl. 25). Dr. Billings’ illustrations give a very fair idea of the
appearance of the appendages, although a little diagrammatic.

Formation and locahty.—Ordovician: Trenton limestone ; Ottawa,
Canada.

Family OLENID Burmeister
Genus TRIARTHRUS Green
TRIARTHRUS BECKI Green

Plate 20, figs. 1-11, Plate 30, figs. 1-20

Triarthrus becki* Green, 1832, Monogr. Trilobites North America, p. 87,
pl. 1, fig. 6. (Original description and illustration.)

Triarthrus becki MATTHEW, 1893, American Jour. Sci., 3d ser., Vol. XLVI,
p. 121, pl. 1, figs. 1-7. (Describes and illustrates antenne, cephalic and
thoracic limbs including endopodite and exopodite of limbs.)

Triarthrus becki BEECHER, 1893, American Jour. Sci., Vol. XLVI, p. 361,
text fig. 1. (Describes mode of occurrence of trilobites with appen-
dages.) Idem, p. 467, text figs. 1-3. (Describes and illustrates thoracic
legs.) Idem, 1894, American Geol., Vol. XIII, pp. 38-43, pl. III, figs. 1-9.
(Describes and illustrates antenne and thoracic limbs, and discusses
mode of occurrence.) Idem, 1894, American Jour. Sci., Vol. XLVII,
Pp. 298-300, text fig. 1, pl. VII, figs. 1-3. (Describes and illustrates
appendages found beneath the pygidium.)

Triarthrus becki Watcott, 1894, Proc. Biol. Soc. Washington, Vol. IX,
pp. 89-97, pl. I, figs. 1-6. (Notes and illustrations of appendages based
on new material.) Idem, 1894, Geol. Mag. London, n. ser., Dec. IV,
Vol. I, pp. 246-251, pl. VIII. (Reprint of preceding paper.)

Triarthrus becki BERNARD, 1894, Quart. Jour. Geol. Soc. London, Vol. 50,
pp. 425, 426, text figs. 11, 12. Idem, 1895, Vol. 51, pp. 352-358. (Repro-
duces two of Beecher’s figures and discusses the structure of the appen-
dages of Triarthrus beckt.)

1In this synonymy the references are only to the original description, and
to other papers containing original description or illustration of the interior
of the dorsal shield or of the ventral appendages.

136 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Triarthrus becki BEECHER, 1895, American Geol., Vol. XV, pp. 93-98, pl. IV.
(Describes and illustrates a unique specimen showing antennz, cephalic
and thoracic limbs.) Idem, 1895, Vol. XVI, p. 172, pl. 8, figs. 12-14,
pl. 10, fig. 1. (Describes theoretical larval stage of Triarthrus becki.)
Idem, 1896, Amer. Jour. Sci., 4th ser., Vol. I, pp. 251-256, pl. VIII, figs. 1,
2. (Describes and illustrates restoration of appendages of Triarthrus
becki and discusses its morphology.) Also printed in Geol. Mag.,
London, Dec. IV, Vol. III, 1896, pp. 193-197, pl. IX, figs. 1, 2.

Triarthrus becki OEHLERT, 1896, Bull. Soc. Geol. France, 3d ser., Vol. XXIV,
pp. 97-116. Text figs. 1-17, 34. (Summarizes and discusses published
data to date on appendages and development.)

Triarthrus becki BEECHER, 1900, Text-book of Pal., Zittel, pp. 615-616, text
figs. 1267-1269, 1300, on p. 629. (Resumé of previous papers on appen-
dages.) Idem, The preceding paper of 1900 was again printed in the
1913 edition of Zittel’s Paleontology with same illustrations and slight
modifications of the text (pp. 700-701, 715, text figs. 1343, 1344, 1345 and -
1375). Idem, 1902, American Jour. Sci., 4th ser., Vol. XIII, pp. 167-174,
pl. 2, figs. 1-5, pl. 3, fig. r, pl. 4, fig. 1, pl. 5, figs. 2-4. (Describes and
illustrates ventral appendages and integument.) Idem, 1902, Geol. Mag.,
London, Dec. X, Vol. IX, pp. 152-162, text figs. 1-3, pls. 9, 10, 11. (Re-
print of preceding paper.)

Triarthrus becki JAEKEL, 1901, Zeits. deut. geol. Gesellsch., Vol. LIII, p. 161,
text fig. 24, p. 162. (Discusses Beecher’s conclusions, proposes new inter-
pretation of appendages, and illustrates fragments of an antenna.)

Triarthrus becki VALIANT, 1901, The Mineral Collector, Vol. VIII, pp. 105-
112. (Account of discovery of appendages and general remarks.)

Triarthrus becki Moserc, 1907, Geol. Foren. Forhandl., Bd. 29, Haft 5, pp.
265-272, pl. 4, fig. 2, pl. 5, fig. 1. (Discusses and illustrates appendages
in connection with supposed appendages of Eurycare angustatum. )

I have long had a sentimental interest in this species largely because
my early home was on a knoll formed of the Utica shale in which
Triarthrus becki occurs, and I collected many specimens of it as a
school-boy in and about the city of Utica. In 1879 I published an
illustrated paper that described the development of the dorsal shield
from the young with one segment to the fully developed individual
with sixteen segments.’ Later Beecher described a younger stage
and in several papers discussed and illustrated the ventral surface
and appendages. It is unfortunate that he did not live to prepare an
extended memoir that he had planned for on its structure. I agree
with his interpretations of the appendages of T. becki except in some
details. His conclusion that the minute elongate lobes beneath the
pygidium were endites of a limb similar to that of Apus,’ is not satis-
factory in view of the appendages found beneath the pygidium of
specimens in the National Museum collections. These are illustrated

Trans. Albany Inst., Vol. X, 1870, pp. 23-33, pl. II, figs. 1-14.
7 American Jour. Sci., Vol. XLVII, 1894, pl. VII, figs. 1-3.

NO. 4 APPENDAGES OF TRILOBITES 137

by figures 4-8, plate 29. Figures 4 and 5 show slender jointed legs
(endopodites) similar to those of the thoracic legs, down to the
extreme end of the body, a structure similar to that found in Neolenus
and Calymene. The setiferous exopodites are also present to the end
of the pygidium. The absence of four expanded subtriangular joints
on each leg in figure 4 may be owing to their absence or to the dorsal
side of the leg being uppermost and the expanded ventral side of the
joints concealed in the rock. This condition of preservation is often
met with in the legs of Marrella* which have expanded joints some-
what similar to those of 7. becki. The specimen represented by
figures 4 and 5 indicates the presence of jointed legs to the end of the
pygidium. With this in view, Beecher’s conclusion that the limbs
beneath the pygidium are similar to those of the young of Apus
requires further consideration. His diagrammatic sketch (loc. cit.,
fig. 3) is very much like that of his figure 4 of Apus, but his figures
I and 2 indicate elongate narrow lobes of nearly equal width through-
out and similar to those seen in our specimen represented by figures 5,
8, 11. That the legs beneath the pygidium in figures 4 and 5 are
typical slender thoracic legs and those beneath the pygidium in
figures 8 and 11 are typical branchiopod (Apus) limbs is not probable
and I am giving in the description of the exopodites a different inter-
pretation to the series of lobes shown in our figures 4, 7, 8 and
Beecher’s figures 1, 2, 3.

The illustrations of the exterior of the dorsal shield are reproduced
on plate 30, but it is unnecessary to reprint the descriptions of the
specimens as the figures are sufficient to serve for comparison of the
dorsal shield with that of other species which have their ventral
appendages described in this paper.

Limes

We owe to Beecher the working out of the epistoma and cephalic
limbs of T. becki, although the antennze found by Valiant had been
described by W. D. Matthew.’ Before considering the true limbs,
mention should be made of the metastoma or lower lip discovered and
described by Beecher * as follows:

The metastoma is generally clearly shown as a convex arcuate plate just
posterior to the extremity of the hypostoma. On each side, at the angles, are
two small elevations, or lappets, which suggest similar structures in many

1 Smithsonian Misc. Coll., Vol. 67, No. 5.
2 American Jour. Sci., 3d ser., Vol. XLVI, 1803, pl. 1, figs. 1-7.
* American Geol., Vol. XV, 1805, p. 97, pl. V, figs. 8-11.

138 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

higher Crustacea, and apparently represent the entire metastoma in Aig and
some other forms. (PI. 32, fig. 1.)

Beecher worked out the thoracic limbs and found them to be
biramous with a strong long proximal joint (protopodite) to which
a jointed leg (endopodite) and a jointed setiferous exopodite were
attached. Unfortunately most of his illustrations are diagrammatic
and give only an approximate idea of the limb. Even the reproduced
photographs ’* given an inadequate conception of the true form of the
limb, especially of the structure of the exopodite.

Cephalic imbs.—Antennules—The anterior antennules or antennz
are uniramose, the exopodite of the primitive limb having dis-
appeared. Each one is composed of a strong basal joint (protopo-
dite) attached to the ventral side of the head at the side of the
hypostoma about midway of its length. The numerous short joints
composing it (pl. 29, fig. 9) each expand slightly at the distal end,
giving it a striking appearance quite unlike the smooth, slender
antennules of Neolenus (pl. 15, fig. 1).

Beecher describes the remaining cephalic appendages as follows: *

First pair of biramous appendages, or posterior antenne—The second pair
of appendages, corresponding to the posterior antenne, are attached to the
head at each side of the glabella, on a line with the extremity of the hypostoma.
They are apparently biramous, and thus agree with the second pair of
nauplian limbs and with the typical posterior antennz of many Entomostraca
and Malacostraca. They may be compared with the posterior antenne in
Euphausia pellucida, one of the schizopods, especially with the Furcilia and
Cyrtopia stages. The details of the endopodite and exopodite are not clearly
shown. The former is more commonly preserved, and its distal joint extends
just beyond the edge of the carapace. The coxopodite is developed into a
triangular plate, the inner angle carrying a masticatory ridge, the whole
extending about three-fourths the distance from the side of the glabella to the
median line, just below the hypostoma, and directly obliquely backwards
(pl. V, figs. 8-11).

Second pair of biramous appendages, or mandibles—The appendages here
correlated with the mandibles are immediately behind the first pair of biramous
limbs. The proximal portion, or coxopodite, is similar in form to the preced-
ing, though somewhat smaller, and overlapping its basal part. The palps, or
endopodial and exopodial branches, have not been distinctly traced, though
their presence is indicated on plate IV, figure 1, where, on the left side, there
are endopodites and exopodites in sufficient number for each appendage of the
head. That these should be referred to the cephalic limbs is further indicated
by their being in advance of the endopodite, which manifestly pertains to the
first thoracic segment. The inner edge of the mandibles as well as that of the

1The Ventral Integument of Trilobites, American Jour. Sci. 4th ser.,

Vol. XIII, 1902, pls. II-V.
2 American Geol., Vol. XV, 1805, pp. 94-95, pls. IV and V.

NO. 4 _ APPENDAGES OF TRILOBITES 139

other gnathobases of the head is apparently finely denticulate, as shown on
plate IV, figure 1, and plate V, figure 2.

Third and fourth biramous appendages, or maxille—Following the appen-
dages referred to the mandibles are two pairs of strong limbs, with broad plate-
like basal portions, or coxopodites, serving as gnathites (pl. V, figs. 8-11).
They resemble each other, and are similar in form to the two preceding limbs,
though somewhat larger. They are usually fairly well preserved and their
form and structure can be approximately made out. The endopodites are com-
posed of stout joints, and could be extended but a short distance beyond the
margin of the head. The exopodites are more slender and carry an abundance
of stiff sete, which often diverge in a fan-like manner from their line of
attachment. These brushes of sete occupying the cavities of the cheeks are
often preserved in specimens where the other details of the limbs are obscure
or obliterated. In Triarthrus they are evidently homologous with similar
brushes observed by Walcott in Calymene.

This completes the number of paired appendages which can be definitely
referred to the head. It is evident they do not differ conspicuously from each
other, and, as will be presently shown, they closely resemble the thoracic legs
in all essential structural characters [Loc. cit., pp. 94-05].

Beecher describes the protopodite of the limbs as follows:

First it has a slender cylindrical form in the posterior half of the series,
then becomes flattened and denticulate, and finally widens, until on the head
it forms the triangular plate-like coxopodite, with masticatory ridge and
functioning as a gnathite [Loc. cit., p. 96].

The study of the material available of the protopodite of Neolenus
--and other trilobites and of the Branchiopoda (Apus) leads me to
conclude that it is fattened and plate-like on all the appendages from
the head to the end of the series beneath the pygidium. It may be
more rounded beneath the pygidium, but the tendency to flat sides
is still shown. The positions and form of the appendages in the
fossil state is no guarantee that they were the same on the living
animal. (See Restoration of ventral appendages, p. 165.)

Thoracic limbs.—These consist of an elongate protopodite to which
the endopodite (leg) is attached and apparently the exopodite.

The protopodite is described by Beecher* as having a slender,
cylindrical form in the posterior half of the series, then becoming
flattened and denticulate, and finally widened, until on the head it
forms the triangular, plate-like protopodite (coxopodite) with mas-
ticatory ridge and functioning as a gnathite. ‘

I have not obtained any additional information about the protop-
odite but from its form in Jsotelus and Neolenus I am inclined to
consider that it may have been flattened on all of the limbs and that

* Bull. Mus. Comp. Zool., Vol. VIII, No. 10, 1881.
? American Geol., Vol. XV, 1895, p. 96.

140 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

its position was, as shown by Beecher in 1895,° vertical to the plane
of the body and not flattened out as shown in his classical restorations
of the ventral side of Triarthrus in 1896.’ In this restoration the
protopodite and the flat joints of the endopodite are on the same plane
which is probably the position they would assume when gradually
forced by compression into one plane, but in a natural position the
protopodite would arch beneath the ventral surface of the mesoster-
nites (axial lobe) and the flat joints would project downward in
the opposite direction as in Beecher’s transverse sections of the
thorax published in 1895 and referred to above.

Endopodite.—This is formed in the anterior portion of the thorax
of four rather long, flattened joints and two relatively short, rounded
distal joints. From the distal end of the last joint a strong spine or
claw with a short spine on each side gives a trifid termination similar
in appearance to that of the leg of Neolenus (pl. 16, fig. 3).

Beecher describes the “ endites ” as follows: ’

The whole series of endopodites anterior to the last two or three show
modifications from the phyllopodous type, the change involving progressively
from one to all of the endites. The endopodites of the pygidium have a true
phyllopodiform structure, and are composed of broad leaf-like joints, wider
than long. This character is gradually lost in passing anteriorly, the distal
endites being the ones first affected. By the time the anterior pygidial limb is
reached, the three distal joints are longitudinally cylindrical. The ninth
thoracic endopodite shows a fourth endite becoming cylindrical, and on the
first and second thoracic legs even the proximal ones are thus modified, making
all the endites of these limbs slender in form.

During my study of the specimens in the National Museum collec-
tions I found that flattening out and enlargement of the joints
(endites) was not always as regular as described by Beecher. Typical
anterior endopodites are illustrated by figure 1, plate 29, and typical
posterior endopodites by figure 20, plate 30. In two instances I found
endopodites that occurred beneath the pygidium with the two distal
endites round and slender (figs. 4, 5, pl. 29) and in one example the
last three distal joints were cylindrical (fig. 7, pl. 29). The joints
(endites) of the endopodite of Marrella splendens are similarly en-
larged by flattening, and extend downward, but as in Triarthrus
they are apparently not constant in size in all specimens.”

Exopodite—The exopodite is nearly as long as the endopodite and
usually much more in evidence in the fossils. It is formed of a

1 American Geol., Vol. XV, 1895, pl. V, figs. 1-4.

2 American Jour. Sci., 4th ser., Vol. I, pl. VIII, fig. 2.

* Idem, p. 253.

* Smithsonian Misc. Coll., Vol. 67. This paper will be No. 5 of this volume.

NO. 4 APPENDAGES OF TRILOBITES I4I

strong, many jointed arm (pl. 29, figs. 2, 11) to which is attached a
diagonally arranged series of bases or supports for strong sete,
which may be jointed near their base and which are extended into
long more or less flattened sete forming a fringe. The jointed
arm appears to be attached to the end of the protopodite beside
the proximal joint of the endopodite. Beecher describes and ilus-
trates a long proximal joint with a denticulated lower edge to which
sete are attached and beyond that a many jointed support; the
proximal joint is represented to be as long as the first and second
proximal joints of the endopodite. In the specimens now available
for study I find that the diagonal crenulations extend up to the point
of attachment of the arm to the protopodite and that there does not
appear to be room for the very long proximal joint illustrated by
Beecher (I have not seen the specimens). The structure of the
exopodite is fairly well shown by figures 2, 3, 8, 10, 11, plate 29. In
figures 2 and 3 the diagonal crenulations outlining the bases of the
sete are shown just beneath the closely jointed supporting arm, also
portions of two of the larger endopodites. Figure 10 has the crenu-
lated structure over the entire supporting arm in such a position that
it appears that it is the upper and posterior side of the arm to which
the crenulations and sete are attached. In figure 11 the anterior and
lower side of the exopodite is shown: it consists of a strong, closely
jointed arm with about twenty segments and a flat, slender, lobe-like
terminal segment or joint; the distal end of the crenulated margin
begins at the proximal end of the terminal section and extends up
along the arm past some twenty segments; the setiferous portion or
fringe is attached to the crenulated portion. The elongate distal
segment of the arm is beautifully shown in figure 8, where numerous
minute exopodites are crowded from beneath the pygidium and the
transversely lobed joints of the arm of the exopodite appear to rest
one on the other. This structure is finely shown on the exopodites of
figures 4 and 5.

The flat, narrow terminal joint of the exopodite is a marked
character (fig. 11) and when a number are grouped beneath the
pygidium (fig. 8, pl. 29) they have the appearance of a series of lobes
somewhat similar to the limb of Apus as suggested by Beecher,’
particularly when the minute exopodites beneath the pygidium have
their joints flattened and drawn out on the posterior side until they
appear like a row of minute, lobe-like exites arranged side by side
so as to give the appearance seen in figures 4 and 5.

* American Jour. Sci., 3d ser., Vol. XLVII, 1804, p. 300, pl. VII, figs. 1, 2, 3.

142 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Beecher, in describing the appendages of Trinucleus concentricus,
said. *

The endopodites on the pygidium offer no conspicuous differences from
those just described, except that a gradual change in form is manifest as the
terminal limbs are reached. The separate endites become more and more
transversely cylindrical, until the whole limb appears to be made up of
cylindrical segments transverse to its length. A similar condition was observed
in the young of Triarthrus?

As I interpret the specimens of T. becki illustrated on plate 29,
figures 4, 5, 8, of this paper, it is the exopodites and not the endop-
odites that have the transversely elongated endites. This is probably
a phyllopod character but not as interpreted by Beecher.

Epipodite——The presence of a flat epipodite attached to the pro-
topodite of the leg near its proximal end cannot be absolutely proven
by the material I have for study but it is quite probable that it existed
as there is on three specimens a flat, elongate oval angular disk or
lobe that is wider than the joint of the limb; it has a distinct margin
on the sides and distal end and in two instances clearly lies above the
limb and resting on it. The anterior margin is slightly arched or
angular and merges into the distal end and the posterior margin has a
slightly angular projection about midway of its length; usually this
lobe is so mashed down on either the proximal joint of the endopodite
or exopodite that it cannot be clearly separated from the limb. On
one specimen preserving several of the probable epipodites (pl. 30,
fig. 19) the distal end is bluntly pointed and the margins have very
fine, short sete projecting from them.

Not one specimen in fifty of Triarthrus becki shows traces of
limbs, and among a hundred or more specimens preserving more or
less of the limbs, only four or five specimens show the long pro-
topodite, hence it is not strange that small epipodites, if they existed,
have not heretofore been found. In the case of the large epipodites
of Neolenus it was only by a fortunate splitting of three fragments
of shale that they were found at all.

Summary.—The appendages of Triarthrus becki are outlined in
the restoration of its ventral side (pl. 32) and the cross-sections on
plate 34. Comparisons between them and the known appendages of
other genera of trilobites may be found under Observations on the
Structure of the Trilobite (pp. 159-161).

Formation and locality—Ordovician: Utica shale; three miles
(4.8 km.) north of Rome, Oneida County, New York.

* American four. Sci., 3d ser., Vol. XLIX, 1895, p. 310.
7 Idem, Vol. XLVII, pl. VII, fig. 3, April, 1894.

NO. 4 APPENDAGES OF TRILOBITES 143

DEVELOPMENT OF TRIARTHRUS BECKI*
Plate 30, figs. 1-15, 18

“ The larval Triarthrus* in its first known stage is ovate in outline,
widest behind, where it also attains its greatest convexity. The
frontal margin is marked by a convex fold of the test. The axis is
annulated. The anterior six annulations apparently belong to the
cephalon, the sixth one being considerably stronger than the others
and probably representing the occipital ring. The pygidial portion
is defined by a narrow, shallow, transverse furrow; and the axis has
two annulations.

“ Near the lateral anterior margins are two slight elevations which
may represent the palpebral lobes of the eyes, and from them extend
two furrows curving inward to the axis and dividing the cephalic
region into two portions. The occipital pleura are indicated by slight
depressions extending from the occipital ring. The specimen illus-
trated by figure 15 has a length of .63 mm. and a width of .46 mm.”

The second known stage has one thoracic segment; the glabella
has broadened in front and the transverse furrows have retreated to
its lateral margins; the occipital segment is strong and carries the
median node that is characteristic on all later stages of growth; fixed
cheeks, narrow and without traces of the palpebral ridge and eye
lobe; a node occurs on the thoracic segment and the pygidium is
elongate with five fused segments in the axial lobe.

There is a gradual increase in size after the first segment is liber-
ated in the thorax, but not of sufficient importance to indicate dis-
tinct periods of development. If any change is to be noted, it is, that,
after the development of the twelfth segment, individuals having
the same number of thoracic segments vary very much in size, some
even being smaller than those having a lesser number of segments;
this period of development is a marked one in the history of this
trilobite, as an individual of thirteen thoracic segments is larger than
one having sixteen. Again we find that an individual of thirteen
thoracic segments is more than three times as large as one with
fourteen, one being twenty-four and the other seven millimeters in
length; that the largest with fourteen segments, thirty millimeters in
length, is nearly double the smallest with sixteen segments, and that
the adult individual of sixteen thoracic segments is fifty-three milli-
meters in length. Minor variations have been noticed in individuals
having less than thirteen thoracic segments, but in no case has the

1Beecher,C. E.: A Larval Form of Trilobite. American Jour. Sci. Vol.
XLVI, 1803, pp. 361-362.

144 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

size of the one having the lesser number of segments exceeded the
next in the series of development. It is not until the twelfth degree
of development is passed that this strange anomaly occurs.’

The pygidium gradually becomes proportionally shorter after the
first stage with one segment and the eye lobe is indicated on indi-
viduals with two segments by a minute groove on the outer border of
the fixed cheek. When the sixth thoracic segment is developed all
parts have attained most of the characters of the adult.’

PTYCHOPARIA CORDILLERZ (Rominger)
Plate 21, figs. 3-5

Conocephalites cordillere RominceER, 1887, Proc. Acad. Nat. Sci. Phil., p. 17,
pl. 1, fig. 7. (Describes and illustrates species.)

Ptychoparia Cordillere Watcott, 1888, Amer. Jour. Sci. 3d ser., Vol.
XXXVI, p. 165. (Refers species to the genus Ptychoparia.)

Ptychoparia cordillere MATTHEW, 1899, Trans. Royal Soc. Canada, 2d ser.,
Vol. V, sec. IV, p. 44, pl. 1, fig. 7. (Describes, comments upon, and gives
diagrammatic illustration of portion of a specimen.)

Ptychoparia Cordillere Woopwarp, 1902, Geol. Mag., new ser., Dec. IV,
Vol. IX, p. 536, text fig. 4. (Notes on species with outline figure of a
dorsal shield.)

Ptychoparia cordillere Watcott, 1908, Canadian Alpine Jour., Vol. I, No. 2,
pl. 3, fig. 5. (Illustrates nearly entire specimen from Mt. Stephen.)
Idem, 1912, Smithsonian Misc. Coll. Vol. 57, p. 190, pl. 24, fig. 2.
(Illustrates specimen showing branchiz (exopodites).)

This species differs from the associated Ptychoparia palliseri in
having a proportionally shorter frontal limb, narrower fixed cheeks,
a less number of thoracic segments, eighteen or nineteen, and absence
of a median node on the anterior thoracic segments. From the asso-
ciated Ptychoparia permulta it varies in its broader fixed cheeks and
frontal limb, rounded instead of spinous genal angles on the cephalon,
_ more numerous thoracic segments, and in having a nearly smooth
surface. Ptychoparia cordillere is quite abundant on Mount Stephen,
and P. permulta is abundant at locality 35k, three miles (4.8 km.)
to the north-northeast.

The dorsal shield of this species is well illustrated by figure 4,
plate 21. The average number of thoracic segments is eighteen, but
one example 23 mm. long has nineteen segments.

Ventral appendages.—Only one specimen has been found showing
the thoracic limbs. This indicates very clearly the general character

* Walcott, C. D.: Fossils of the Utica Slate. Trans. Albany Inst., Vol. X,
1879, p. 29 (Advance print). .
* Idem, pp. 26-29.

NO. 4- APPENDAGES OF TRILOBITES 145

of the exopodite and that it is situated above the endopodite, although
there are only imperfect traces of the latter projecting from beneath

_ the exopodites as shown in figure 5, plate 21.

The exopodites are unlike those of any trilobite now known. They
are long, rather broad lobes extending from the line of the union of
the mesosternites and the pleurosternites. At the proximal end they
appear to be as wide as the axial lobe of each segment, and to increase
in width and slightly overlap each other nearly out to the distal
extremity. They appear to have extended beyond the dorsal shield,
but not as far out as the extremity of the leg (endopodite). They
are finely crenulated along both the anterior and dorsal margins
which indicates the presence of fine sete.

Formation and locality—Middle Cambrian: (14s) Ogygopsis
zone of the Stephen formation ; about 2,300 feet (701 m.) above the
Lower Cambrian and 3,540 feet (1,089 m.) below the Upper Cambrian,
at the great “ fossil bed” on the northwest slope of Mount Stephen,
above Field on the Canadian Pacific Railroad; (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass, above Field; (61j) yellow weathering band of
calcareo-argillaceous shale, west slope of Mount Field, near Burgess
Pass ridge, about 3,000 feet above Field, and (58r) about-2,200 feet
(676.9 m.) above the Lower Cambrian, and 3,725 feet (1,146 m.)
below the Upper Cambrian, in the limestones forming 2 of the
Stephen formation, in the amphitheater between Mounts Stephen
and Dennis, above Field, British Columbia, Canada.

PTYCHOPARIA PERMULTA, new species
Plate 21, figs. I, 2

Dorsal shield —Dorsal shield rather small and delicate, elongate
ovate in outlines, probably quite sharply flexed at the geniculation
before being flattened in the shale; its greatest width approximately
two-thirds its length.

Cephalon.—Cephalon a little more than one-third as long as the
entire shield, semielliptical in outline. Glabella long and slender,
moderately elevated along an obtuse medial ridge which is highest a
little behind the anterior extremity ; dorsal furrows rather broad, not
very sharply incised, slightly converging; anterior extremity of the
glabella about two-thirds as wide as the base, broadly rounded;
anterior furrow much more shallow than the dorsal; glabellar
furrows very distinct in the younger forms, the medial and anterior
pairs usually obscure in the older; posterior pair strongly oblique,

146 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

persistent to the occipital ring which they intercept a little to the side
of the median line; medial and anterior pairs linear, the medial pair
very slightly oblique, the anterior nearly at right angles to the axis;
occipital furrow rather broad, uniform in depth; occipital ring rather
narrow, not nodulated, similar in character to the anterior segments
of the thorax. Fixed cheeks low and wide, the distance from the
palpebral lobe to the dorsal furrows about two-thirds the width of the
medial portion of the glabella; posterolateral lobe short and broad,
obtuse at the distal extremity ; posterior groove deep, smoothly con--
cave, in line with the occipital furrow. Palpebral lobe very short,
contained more than three times in the length of the glabella, rather
narrow and nearly parallel to the dorsal furrow, placed opposite the
medial glabellar furrows. Palpebral ridge usually obscure, intercept-
ing the dorsal furrows directly behind the anterior extremities.
Frontal limb very narrow in the young, wide and broadly inflated in
the adult. Frontal border narrow, upturned, cut off from the limb by
a smoothly concave depression. Facial sutures with the posterior and
anterior sections oblique and converging toward the short palpebral
lobe. Free cheeks usually attached, of approximately the same width
as the fixed cheeks. Peripheral border, like the frontal border,
elevated and upturned and, like it, cut off from the inner portion by a
smoothly rounded groove which intercepts the occipital groove at
nearly a right angle; genal angles produced into short but acute
spines which terminate opposite the second thoracic segment.

Thorax.—Thoracic segments normally fourteen in number. Axial
lobe not very strongly convex, of about the same width as the
proximal portion of the pleura ; axial annulations narrow and sharply
defined, but not nodose. Pleural segments narrow, very compactly
arranged, the fourth to the ninth the most produced; pleural furrows
almost as wide as the including segment, smoothly rounded; ex-
tremities petaloid ; posterior inclination very slight.

Pygidium.—Pygidium short, a little more than twice as broad as it
is long. Axial lobe relatively broad, truncate at the extremity which
falls a little in front of the posterior margin; axial annulations, with
the exception of the anterior, obscure, indicating three component
segments and a terminal section. Pleural lobes small; pleural fur-
rows distinct anteriorly, obsolete posteriorly, parallel to the anterior
margin. Posterior margin an arc of a little less than 180°.

Surface-—Entire external surface finely and closely tuberculated ;
tubercles most crowded upon the cephalon ; venation upon the frontal
limb well developed.

NO. 4 APPENDAGES OF TRILOBITES 147

Dimensions.—Length of dorsal shield, 25.5 mm.; greatest width
of dorsal shield, 17.2 mm.; length of cranidium, 11.0 mm.; length of
glabella, 7.0 mm.

Type locality —(35k) One mile northeast of Burgess Pass, British
Columbia.

Observations —This fine species is associated with Ptychoparia
cordillere and P. palliseri in the large Burgess shale fauna. It differs
from the former in having a tuberculated surface, narrower fixed
cheeks, longer frontal limb, spines on genal angles of free cheeks,
fewer thoracic segments (four to five less in number), and from
P. palliseri in the same characters except that the latter has six to
seven more thoracic segments, and a somewhat narrower fixed cheek
but broader than that of P. permulta.

One specimen has two antennules attached, which is the reason for
noticing the species in this paper. The antennz are so flattened in
the shale that all traces of the joints are lost. As far as known to me
it is the only specimen of the genus Ptychoparia preserving even the
outline of the anterior antennz (antennules).

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass; and (148) Ogygopsis zone of the Stephen forma-
tion ; about 2,300 feet (701 m.) above the Lower Cambrian and 3,540
feet (1,089 m.) below the Upper Cambrian, at the great “ fossil bed ”
on the northwest slope of Mount Stephen, both above Field on the
Canadian Pacific Railroad, British Columbia, Canada.

Order PROPARIA Beecher

Family CALYMENIDZ: Milne-Edwards
Genus CALYMENE Brongniart
CALYMENE SENARIA Conrad, 1841
Plates 26, 27, 28, 33 ‘

Calymene senaria Conrad, 1841, Fifth Ann. Rept., New York Geol. Surv.,
pp. 38, 49. (Name proposed with brief description.)

Calymene senaria* Watcort, 1876, Twenty-eighth Ann. Rept., New York
State Mus. Nat. Hist., pp. 89-92. (Notes discovery of natatory and
branchial appendages of trilobites in Trenton limestone.) Idem, 1879,
Thirty-first Ann. Rept. New York State Mus. Nat. Hist., p. 61, pl. 1,

1In the synonymy the references are to the original description and to
papers containing description or illustration of the interior of the dorsal shield
or of the appendages. No attempt is made to give all references to the species.

148 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

figs. I, 2, 5. (Notes and illustrations of cephalic and thoracic appen-
dages.) Idem, 1881, Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII,
pp. 198-216, pls. 1-6. (Description and illustrations of cephalic, thoracic
and pygidial limbs with restoration of ventral surface of body with
legs (endopodites) and a transverse section of the thorax with limbs
attached.) Idem, 1884, Science, Vol. III, p. 279, figs. 2, 3. (Refers to
Calymene in note on appendages of the trilobite.) Idem, 1894, Proceed.
Biol. Soc. Washington, Vol. IX, p. 90, pl. 1, fig. 7. (Refers to discovery
of an antennule-like appendage in Calymene senaria.) Also printed in
Geol. Mag., London, n. ser., Dec. IV, Vol. I, p. 246.
As the sections of the appendages of Calymene senaria and
Ceraurus pleurexanthemus have many similar characters the notes
on them will be combined under the latter species.

Family CHEIRURID& Salter
Genus CERAURUS Green
CERAURUS PLEUREXANTHEMUS Green
Plates 26, 27, 28

Ceraurus pleurexanthemus GREEN, 1832, Monogr. Trilobites North America,
p. 84, text fig. ro. (Original figure.)

Ceraurus pleurexanthemus Watcott, 1875, Ann. Lyc. Nat. Hist., New York,
Vol. XI, pp. 155-162, pl. XI. (Describes and illustrates interior of dorsal
shield.) Idem, 1876, Twenty-eighth Ann. Rept. New York State Mus.
Nat. Hist., pp. 89-92. (Notes discovery of natatory and branchial appen-
dages of Trilobites in Trenton limestone.) Idem, 1879, Thirty-first Ann.
Rept. New York State Mus. Nat. Hist., p. 61, pl. I, fig. 3. (Describes and
illustrates thoracic leg of Ceraurus.) Idem, 1881, Bull. Mus. Comp.
Zool., Harvard Coll., Vol. VIII, pp. 191-216, pls. 1-4, 6. (Describes and
illustrates sections of this species, showing appendages and gives a
restoration of thoracic legs.) Idem, 1884, Science, Vol. III, p. 279.
(Refers to Ceraurus in note on appendages of trilobites.)

The investigation made by me from 1875 to 1880 by cutting thin
sections of specimens preserved in a limestone matrix resulted in
determining the general character of the appendages of Calymene
senaria and Ceraurus pleurexanthemus. The restorations of 1881
failed, however, to show the presence of antennz, the form and size
of the protopodite or proximal joint of the thoracic and abdominal
limbs, and there may have been an error in the restoration of the
large distal joints of the fourth or posterior pair of cephalic legs.
The antennules and the evidence indicating the larger, more elongate
character of the protopodite (proximal joint) of the thoracic and
abdominal limbs were not discovered and interpreted until after the
publication of my paper of 1881.

1 Walcott, Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, No. to, 1881,
pp. 198-224, pls. 1-6.

NO. 4 APPENDAGES OF TRILOBITES 149

CEPHALIC LimMBs

Antennules——The occurrence of what might be the longitudinal
section or part of an antenna or antennule was known to me in 1882,
but it was not until 1894 that reference to’ it was made as indicating
an antennule. The section showing it cut through the head of an
enrolled specimen of Calymene senaria, and near the cross-section of
the hypostoma showed a longitudinal section of a slender jointed
antenna-like rod sloping upward while the limbs sloped diagonally
outward and downward. With our present information of the
antennules of Triarthrus and Neolenus there is little doubt but that an
antennule of Calymene is cut across by the section. Attempts to
photograph it have been unsatisfactory owing to the density of the
section.

Endopodite.—The protopodite of the first, second and third pair
of cephalic limbs is smaller and the following joints are more slender
than those of the fourth (figs. 6, 9, 11, pl. 26) pair and the limbs of
the thorax. Traces of fine spines were seen on the inner end of the
protopodite in some of the sections, which indicates that the pro-
topodite functioned more or less as a gnathite. My conception of
the relative position and form of the limbs is indicated by the resto-
ration on plate 33.

In the restoration of 1881 of Calymene the enlarged distal joints
of the posterior pair of cephalic legs (endopodites) were based upon
evidence afforded by several slides, four of which are illustrated by
figures 9, 10, 12, and 13, plate 26. If such broad joints were present,
sections like those in the figures mentioned must result if the section
cut through the broader axis of the joint. If it cut through the
narrow axis, sections like those represented by figure 11, plate 26,
would result. The sections mentioned appear to be best explained
by assuming the presence of large, flat distal joints on the posterior
cephalic legs, and I am now putting them in the restoration of
Calymene senaria (pl. 33, fig. 1), although such expanded joints are
unknown in Neolenus and Triarthrus. Probably the broad, flat joints
were used in swimming, as the other known appendages are not very
well adapted for the purpose.

Exopodite—Sections cut through the heads of many specimens of
both Calymene and Ceraurus showed more or less of the cephalic
legs and the setiferous epipodites, but only rarely was a trace of the
spiral exopodite met with. In fact, in only one instance was there

* Note on some Appendages of the Trilobites, Proc. Biol. Soc. Washington,
Vol. IX, p. 90.

150 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

apparently evidence that the spiral belonged to a cephalic limb and in
this there was no direct connection shown. There probably was a
small exopodite attached to the large protopodite of the posterior
cephalic limbs, and a more or less rudimentary one present on the
three anterior pairs as short, slender, wire-like or flattened ribbons.

Epipodite-——The presence of flat setiferous lobes beneath the
cephalic shield was known in 1881,’ but the interpretation of their
relations to the limbs was not then attempted. Comparing the lobes
with those attached to the cephalic limbs of Neolenus (pl. 16, figs.
1, 2) we find that the setiferous lobes of Calymene and Ceraurus are
relatively smaller, shorter, and bear stronger sete. This is shown by
figure 2, plate 26, and figure 14, plate 27 (Ceraurus), and possibly by
figure 11 (Calymene). In figure 11, plate 27, the lobe is merged into
the mass filling the central part of the space beneath the head, but in
figure 12 the lobe is detached on the right side, although it is close
to the large protopodite of the posterior cephalic limb to which it was
probably attached very much as a similar lobe is attached to the
protopodite of the thoracic limbs: (pl. 27, fig. 14, left side, and
pl:26, fie. 2) left side).

TuHoracic Limss

The restoration of the thoracic limb of Calymene shows a large
elongate protopodite, an endopodite, a curious, slender, bifid, spiral
exopodite, and a lobe-like setiferous epipodite. The relative positions
of the parts are indicated in the restoration, figure 6, plate 35.

Protopodite——In the case of the proximal joint (protopodite) of
the thoracic limbs there is every reason to change my restoration of
1881 and replace the relatively short joint with a long joint that
extends inward on each side of the longitudinal axis of the ventral
surface about one-third the distance across the axial lobe. This
change is based on such sections as those illustrated by figures 1-8,
plate 26, and such proximal joints are characteristic of the limbs
of Neolenus, Triarthrus, and Isotelus. Each of these sections repre-
sented by figures 1-8 clearly indicates strong, elongate, proximal
joints, and those represented by figures 4 and 15 had short, strong
spines on the proximal end. It is surprising that such good results
were obtained by cutting sections, but these illustrated (figs. 1-8) are
selected from among hundreds that did not happen to cut through
the limbs at the right angle to show definitely their size and form.

*Walcott, Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, No. 10, 1881.
pl. 3, figs. 1 and 2.

NO. 4 APPENDAGES OF TRILOBITES I51

The proximal joints shown in the restorations of 1881 were correct
for transverse and closely associated sections, but not for the longi-
tudinal section of the limb. The form now assumed to be nearly
correct for the protopodite is shown by figures 1-8 of plate 26, and
by the restoration, figure 1, plate 33.

Endopodite——The endopodite is formed of six slender joints, the
two and it may be three proximal ones being more or less flattened
and the distal joints more cylindrical and terminating in a short
curved hook or claw and two short spines as in Neolenus. The joints
of the endopodite of Ceraurus appear to have been more expanded at
the distal end than those of Calymene. This is indicated in the
restoration of the cross-section of the dorsal shield and ventral
appendages (pl. 34, fig. 1).

Exopodite—tThe exopodite is apparently situated between the
endopodite and epipodite, but the exact point at which it was attached
to the protopodite is unknown, but from comparisons with Neolenus
and the Anaspids (Malacostraca) the attachment was presumably
at the distal end of the protopodite.

The first or proximal portion or base was slender and elongate
and from it a bifid, slender, wire-like spiral curved outward and
downward so as to be above and free from the leg (endopodite)
(pl. 27, figs, 2,4, and 5). The sections apparently cut across strong,
closely coiled spirals that had sufficient rigidity to usually retain
their form even when they were crowded together (pl. 27, figs. 4, 6,
8,9). Occasionally there is a partially drawn-out spiral (fig. 7) or
it may have been pulled out into a straight wire or a ribbon (pl. 26,
fig. 14).

I was greatly puzzled by the spirals when I began cutting sections
of Calymene and Ceraurus in 1875 and endeavored to find something
indicating a long linear support, but in no instance has a trace of such
been found or an indication of attached sete. The latter abound in
some sections of Calymene and Ceraurus, but they belong with the
epipodites. When the exopodite of Triarthrus was found to have
obliquely arranged sete supported by a jointed arm it seemed as
though the problem was solved, but it was soon found (1894) that
these were attached to a strong jointed exopodite and did not have a
spiral structure. I have more recently worked out and studied several
exopodites of Triarthrus and have confirmed my former opinion that
no sections of them could give the spiral structure shown by the spiral
exopodites of both Calymene and Ceraurus.

Longitudinal and oblique sections of closely coiled spirals of wire
set in plaster and cut across are identical in form with the spirals in

152 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the trilobite sections (pl. 27, figs. 10, Ioa). In fact practically
every section of the fossil spirals illustrated on plate 27 may be
duplicated by making close coils of wire of various sizes and bending
them to secure the right longitudinal curvature before embedding in
plaster. Elongated or drawn out spirals such as shown in figures 6
and 7 are also easily produced.

E pipodite—Sections of a setiferous lobe indicate the presence of
an epipodite. It appears to have been flat with a fringe of long,
strong, simple setae as shown by figures 12 and 14, plate 27; figure 2,
plate 26. In the latter figure and in figure 13, plate 27, the sete of
several epipodites appear to have been cut across so as to give the
effect of long rows of sete. The same condition occurs in specimens
of Marrella when the setz of several exopodites are matted against
each other.”

Two sections show an epipodite near their point of attachment to
the protopodite. In figure 12, plate 27, this is shown on both sides
not far from the cephalon, and in figure 2, plate 26, on the left side
and well back in the thorax.

From these sections I infer that the epipodite was attached to the
protopodite well out towards its distal end.

Other sections show the base of the spiral exopodite in the same
position, a fact not at all surprising as the exopodite and epipodite
may be either accidentally or actually nearly on the same line with
relation to the leg (endopodite).

There are two sections (pl. 27, fig. 4) of an enrolled Calymene that
suggest a small, slender appendage with two long joints, the distal
one having a few minute setz along its outer side. Whether this is a
flattened leg (endopodite) cut across on its narrow section or a part
of an appendage with which we are not acquainted is difficult to
decide with only one indefinite specimen available for study.

Of the appendages beneath the pygidium I wrote in 1881:

The character of the appendages beneath the pygidium is one of unusual
interest, and for a long time was highly problematical, and at present the
evidence is not all that could be desired. Four sections, two transverse and two
longitudinal, show their presence in Ceraurus. That they are jointed is shown
by plate II, figure 8, and also in a similar section not illustrated. A transverse
section, plate II, figure 4, of the extreme posterior segment of the pygidium
also shows the base of the leg and sections of the succeeding anterior legs.
The position of the base is the same as that of the posterior leg, plate II,
figure 8. That these legs were not foliaceous and branchial is evident, but

what their terminal joints were like is yet an unsettled problem of the
investigation.”

* Plate 25, figs. 3, 6, Smithsonian Misc. Coll., Vol. 57.
? Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, No. 10, 1881, p. 204.

NO. 4 APPENDAGES OF TRILOBITES 153

We have no further information except that from the character
of the appendages beneath the pygidium of Triarthrus and Neolenus
it is probable almost to a certainty that the limbs were similar to those
of the thoracic region.

Further description and discussion of the appendages and structure
of Calymene and Ceraurus is given in the general discussion, also in
the description of illustrations and the restorations.

Formation and locality—The specimens preserving appendages
and illustrated are from the Ordovician: Trenton limestone (upper
section) : One mile. (1.6 km.) east of the middle fall of Trenton
Falls, on the West Canada Creek, in the town of Russia, Herkimer
County, New York.

ODONTOPLEURA TRENTONENSIS (Hall)

Acidaspis trentonensis Hatt, 1847, Nat. Hist. Surv. New York, Pal., Vol. I,
p. 240, pl. 64, figs. 4a-f. (Describes and illustrates species.)

Acidaspis Trentonensis Watcott, 1881, Bull. Mus. Comp. Zool., Harvard
College, Vol. VIII, p. 206. (Refers to appendages of.)

Odontopleura trentonensis CLARKE, 1892, Forty-fourth Rept. New York
State Mus., p. 101. (Changes generic refererices.)

In this species fragments of both cephalic and thoracic limbs have
been observed with the endopodite and exopodite apparently of the
same character as those of Calymene and Ceraurus with which they
were associated.

Formation and locality—The specimens preserving appendages
are from the Ordovician: Trenton limestone (upper portion) : One
mile (1.6 km.) east of the middle fall of Trenton Falls, on the West
Canada Creek, in the town of Russia, Herkimer County, New York.

Order HYPOPARIA Beecher
Family TRINUCLEIDAZ Emmrich
Genus TRINUCLEUS Murch
TRINUCLEUS CONCENTRICUS Eaton

Dr. C. E. Beecher found traces of the thoracic limbs of this species,
which indicate that they were essentially of the same type of those of
Triarthrus becki with which the specimens of T. concentricus were
associated * at the locality near Rome, New York.

*Structure and Appendages of Trinucleus. American Jour. Sci., 3d ser.,
Vol. XLIX, 1895, pp. 307-311, pl. III.

154 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

ORDOVICIAN CRUSTACEAN LEG
Plate 36, figs. 1, 2, 2a-d

A crustacean leg, represented by several specimens, occurs on the
surface of a fragment of calcareous shale of Ordovician age from
Ohio. It is quite unlike the leg of Neolenus, Triarthrus, or Isotelus.
The proximal joints, coxopodite and basopodite are very short and
provided with two sharp processes on the ventral side; the third joint
is somewhat similar to the second but is longer ; the next four are of
nearly equal length and might be compared with second, third, and
fourth joints of the leg of Neolenus,; the distal joint is long, slender,
and without a terminal claw. The ventral side of the joints’ has a
fine crenulation indicating the bases of sete. The unusually fine
drawing of a leg made by Mr. Clarence R. Shoemaker shows that the
joints were united by a thin membrane that did not resist destruction
so well as the thin integument forming the covering of the joints.

The legs are associated with fragments of Calymene meeki, but it
is not probable they belong to that species ; if they did, they are unlike
any trilobite leg known to me. The very short coxopodite and baso-
podite are unknown in the trilobites of which we have the legs, as they
are fused into one joint forming the long protopodite in the trilobite.
The distal joint is also unlike that of the trilobite legs known to us.
The leg (pl. 36, fig. 1) is more like one that we might expect in an
Isopod. The legs average about Io mm. in length. One was illus-
trated by me in 1881."

Formation and locality—Ordovician: Cincinnatian, Cynthiana
limestone. Bank of Ohio River below Covington, Kenton County,
Kentucky.

SECTION 2
STRUCTURE OF THE TRILOBITE

Dorsal shield —The structure of the. dorsal shield and hypostoma
of the trilobite is so well known that it is unnecessary to discuss it
further than to state that the known range of variation in form and
segmentation is so great that it undoubtedly has affected the details
of the ventral appendages but not their fundamental arrangement and
structure.

* Bull. Museum Comp. Zool., Harvard College, Vol. VIII, pp. 204, 224, pl. VI,
fig. Sa.

NO. 4 APPENDAGES OF TRILOBITES 155

The structure of the ventral surface, intestinal canal, and appen-
dages will be considered and incidental reference made to the possible
position of the organs within the visceral cavity.

Ventral integument.—Beecher has reviewed the evidence bearing
on the structure of the ventral integument * briefly and concisely and
summed it up as follows:

The ventral integument in trilobites is a thin uncalcified membrane, which
may be divided into pleurosternites and mesosternites, corresponding to the
mesotergites and pleurotergites of the dorsal test, and like them connected
segmentally by an inarticular membrane.

The mesosternites are usually marked by five longitudinal ridges, or but-
tresses, representing thickenings of the membrane, which may be homologized

with apodemal structures in other crustacea, and not with the appendicular
system.

These buttresses, or apodemes, include a single median one for each
mesosternite, with two others on each side extending forward and obliquely
inward, and enclosing subtriangular or rhombic spaces.

The presence and disposition of these buttresses apparently afford informa-
tion regarding the ventral musculature of the trilobites. A pair of flexors is
indicated, together with the lateral strands attached to each mesosternite and
extending forward and inward to their union with the main bundles within the
cavity of the next anterior somite.”

My present review has not led to the discovery of additional evi-
dence, and I agree with Beecher that Jaekel was greatly misled in his
interpretation of the cast of the ventral membrane of Ptychoparia
striata, and that he was led on the evidence furnished by this one
specimen of Ptychoparia “ to reconsider on a false premise the entire
question of the anatomy, ontogeny, phylogeny, and affinities of the
trilobite.” *

In connection with my investigation of the structure of ventral
integument and appendages of Calymene and*Ceraurus I found ° that
in those longitudinal sections in which the ventral integument is most
perfectly preserved it had been a thin, delicate pellicle or membrane,
strengthened in each segment by a transverse arch. These arches ap-
pear as flat bands separated by a thin connecting membrane, some-
what as the arches in the ventral surface of some of the Macrouran
Decapods. The finest illustrations of this structure have been found

* American Jour. Sci., 4th ser., Vol. XIII, 1902, pp. 165-174.

* Idem, p. 172.

§Jaekel, Otto.—Beitrage zur Beurtheilung der Trilobiten. Theil I. Zeits.
deut. Geol. Gesells., Bd. LIII, Heft 1, 1901, pp. 133-171, figs. 1-31, pls. IV-VI.

*Beecher, C. E., American Jour. Sci., 4th ser., Vol. XIII, 1902, p. 166.

* Walcott, C. D.: The Trilobite: New and Old Evidence relating to its
Organization. Bull. Mus. Comp. Zool., 1881, Harvard Coll., Vol. VIII, No. ro.
pp. 199-200.

156 SMITHSONIAN MISCELLANEOUS: COLLECTIONS VOL. 67

in Calymene, but several sections of Ceraurus show it very well de-
fined. The section represented on plate 28, figure 8, gives a very fine
view of the membrane and arches in a longitudinal section. The
specimen illustrated on plate 28, figure 7, shows a portion of the
dorsal shell of the median lobe broken away so as to exhibit the open-
ings in the ventral surface that gave passage to the muscles, etc., of
the legs, the partitions separating the segments of the ventral surface,
and the central ridge to which they are attached. This ridge, with the
partitions and arches in the membrane beneath, would give the neces-
sary strength and firmness to form the base of attachment of the
limbs. The membrane uniting the margins of the dorsal shell and the
median lobe of the ventral surface curves upward close to the pleural
lobes of the dorsal shell, and leaves but a narrow space between it and
the dorsal shell.

In by far the greater number of sections, both transverse and
longitudinal, the evidence of the former presence of an exterior mem-
brane protecting the contents of the visceral cavity, rests on the fact
that the sections show a definite boundary line between the white
calespar, filling the space formerly occupied by the viscera, and the
dark limestone matrix. Even the thickened arches are rarely seen.
This is almost universally the case with the legs and attached appen-
dages, as their external membrane is not to be distinguished as such.
It would appear that in the process of mineralization the calespar
that replaced the viscera and contents of the appendages also replaced
the substance of the membrane, thus forming one continuous mass
and effacing all traces of the delicate external test. The nature of
this covering is also shown by the present imperfect condition of the
appendages. Only in a few rare instances are they found in an
approximately perfect state, and the many bizarre forms prove that
it was semielastic, and forced into many irregular forms.

On the same small block of limestone with the two jointed legs
illustrated on plate 36, figures 2, 2a-d, occur the remains of the dorsal
shell of both Calymene senaria and Trinucleus concentricus. The
contrast in the test of the joints forming the legs and that of the
dorsal shell is very striking. The latter is firm, thick, and of a yellow
or opalescent color, while the former is of a bronze color, thin and
indented with numerous imprints as though it had contracted or
shrunk after the decomposition of the muscles of the leg.

The intestinal canal..—Attention was first called to the existence of

*Walcott, C. D.: The Trilobite: New and Old Evidence relating to its
Organization. Bull. Mus. Comp. Zool., 1881, Harvard Coll., Vol. VIII, No. to,
Ppp. 200-201.

NOnAY APPENDAGES OF TRILOBITES 157

the intestinal canal in the trilobite by Prof. Beyrich, who discovered
it in a specimen of Trinucleus ornatus.’ M. Barrande subsequently
gave numerous illustrations of its preservation in Trinucleus gold-
fussi, where, he says, it extended from the middle of the glabella
along the interior of the median lobe to the extremity of the pygidium.
In some examples it is filled with very fine, soft clay. This sub-
stance has, perhaps, largely contributed to preserve the form of the
canal, which, once filled and buried in incompressible sand, has under-
gone no other deformation. There must have been some peculiarity
of conformation that preserved the intestinal canal in this species, as
in other trilobites from the same quartzites no traces of it are to be
seen. M. Barrande mentions that Dr. A. de Volborth discovered in
an [/llenus a lengthened and articulate organ which originated in the
glabella and became attenuated toward the pygidium.’ A cast of the
interior, as shown in plate 28, figure 7, might have such an appear-
ance. This, however, is conjectural, as I have not seen an illustration
of Dr. Volborth’s specimen.

In my cutting of sections of trilobites it was a very rare occurrence
to find traces of the intestinal canal. One specimen out of one
hundred was a large proportion. The visceral cavity was usually
filled with calespar, and all vestiges of the canal or any other organ
obliterated.

In a note taken while cutting sections in December, 1876, it is
stated that when grinding down a section from the anterior towards
the posterior extremity of the head the cephalic cavity which was
filled with calcspar, had a dark, round spot midway between the
hypostoma and median lobe of the head. A sketch taken after the
grinding had carried the section a short distance back shows the dark
spot with the same outline as the opening seen in plate 28, figure 4,
that leads into the intestinal canal from the cephalic cavity as exposed
in the specimen. That this was the normal form of the intestinal
canal is doubtful, but the transverse section, plate 28, figure 5, shows
the opening in figure 4 divided into two openings caused in all prob-
ability by the ventral integument with its central ridge, having been
pressed up against it. In several transverse sections a round, dark
spot is seen in the spar a little distance beneath the thoracic segments.
This was filled with sediment or food, and thus distinctly outlined.

1Ueb. Trilob., II. Sttick, p. 30, pl. IV, fig. 1c, 1846.
2 Sys. Sil. Boh., I., p. 229, 1852.
®Tdem, II, p. 182, 1872.

158 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The position of the opening of the canal in the specimen repre-
sented by figure 4, plate 28, and in the section ground away, would
indicate that it passed beneath the cephalic shield into the cephalic
cavity, and then recurved to the opening of the mouth. Pos-
teriorly it extended to the extremity of the pygidium, as described
by M. Barrande.

The space occupied by the canal and other internal organs is not
large, as it is contained mostly between the arched median lobe of
the dorsal shell and the ventral membrane, as shown in the restora-
tions of the cross-sections of the thorax (plate 34).

APPENDAGES
LIMBS

The hypostoma, metastoma, and caudal rami are not treated as true
limbs.

The limbs are essentially the same for all of the trilobites of which
we now know them (pl. 35, figs. 4-7). They have with the exception
of the antennz a protopodite bearing two rami, the endopodite and
the exopodite. The coxopodite and basopodite of the theoretical
primitive crustacean limb is fused into one large joint which in this
paper will be designated as the proximal joint or protopodite. To
this stem or base there is attached a strong jointed endopodite or
walking leg and an exopodite varying greatly in form and structure,
but always present in those trilobites of which we have the limbs
well preserved, except possibly on some of the cephalic limbs. The
protopodite may also bear one or more appendages known as the
epipodite and possibly another lobe or exite. In the antennz the
exopodite has disappeared, leaving only the simple jointed endop-
odite. The various joints of the limb were probably connected by a
thin flexible membrane protecting the muscles as with recent
crustaceans. Some of the details of the limbs will be found in the
description of the appendages of the several species.

Antennules—The antennule of the trilobite is formed of a simple,
jointed endopodite, the exopodite of the primitive limb having dis-
appeared. In Triarthrus the long, slender antennules are composed
of a strong, elongate basal joint (protopodite) attached to the ventral
side of the head beside the hypostoma ; the remaining joints are short
and expand slightly at the distal end (pl. 32, fig. 1). In Neolenus
(pl. 31) the joints of the antennules are much like those of Triarthrus,
but there is less expansion at the distal end of each joint which results

INOSTAT . APPENDAGES OF TRILOBITES 159

in a smoother, more cylindrical surface. The antennules of Ptycho-
paria are too imperfect to obtain details, but they appear to be similar
to those of Neolenus.

Protopodite——The protopodite is now fairly well known for the
limb of the Ordovician species, Calymene senaria, Ceraurus pleurex-
anthemus, Triarthrus becki, Isotelus maximus, and particularly well
for the Cambrian species Neolenus serratus. In all, it is large,
elongate, and presumably formed of two fused joints, the coxopodite
and basopodite. No traces have been seen of a precoxal joint. In
all but Triarthrus the point of attachment to the ventral surface of
the body appears to have been about midway and in Triarthrus
nearer the distal end. The exact form of attachment to the ventral
integument is unknown, but as stated under Neolenus it was prob-
ably narrow and long and connected the dorsal side of the protopodite
with the ventral integument and interior supports somewhat as the
limbs of Apus and Limulus are attached to the body. The original
form of the protopodite is not fully preserved in any specimen known
to me, but from Beecher’s specimens a fairly accurate idea may be
obtained for Triarthrus and from the flattened specimens found in
Neolenus it appears that the cross-section is much like that of the
protopodite of Apus (pl. 36, fig. 4), and another suggestion is
obtained by comparing it with the leg of Limulus. In Apus and
Limulus the protopodite is flat with the nearly vertical sides, and the
proximal margin thin with rows of fine spines that continue more or
less along the ventral margin towards its distal end. A longitudinal
outline of the protopodite of Neolenus as restored is shown by figure
4, plate 35, and this may have been the section of the protopodite of
nearly all trilobite limbs as they appear to have had the same function
in all the genera in which they are now known.

Endopodite——The endopodite or leg extends outward from the
distal end of the protopodite. It is composed of six joints and a short
curved terminal claw with two short spines projecting from near
the base of the claw. The joints vary in length and relative size in
the several species now known. They appear to be essentially the
same in form for Calymene and Triarthrus, but in Triarthrus they
extend further beyond the edge of the dorsal shield as the pleural
lobes of the latter are proportionally narrower. In Neolenus the
legs extend beyond the dorsal shield very much as in Triarthrus, but
not quite as far. Calymene, Ceraurus, and Jsotelus are often found
enrolled, which indicates that the legs could be drawn within the
margin of the shield.

160 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Exopodite—The exopodite appears to spring from or near the
distal end of the protopodite. It varies from the bifid spiral of
Calymene and Ceraurus to the simple, two-jointed, broad, flat, setif-
erous lobe of Neolenus and the many jointed, complicated, setif-
erous exopodite of Triarthrus. A setiferous exopodite is indicated
for Ptychoparia, Isotelus, and Trinucleus, but the structure is
unknown.

Epipodite—The large epipodite of Neolenus (pl. 20, figs. 3, 4) is
a flat, two-jointed elongate lobe attached to the protopodite and reach-
ing out to the edge of the carapace. A second and much smaller
elongate lobe is indicated on one specimen that was attached near the
larger lobe (pl. 18, fig. 2). A small setiferous epipodite is attached
to the protopodite of Calymene (pl. 35, fig. 6) and Triarthrus seems
to have a small, flat, oval, finely setiferous lobe in about the same
place (pl. 30, fig. 19).

Exite——What may be an exite on the protopodite of Neolenus is
shown on figures 3 and 4, plate 20. Its assumed position is indicated
on the restoration of this species (pl. 18, fig. 2, and pl. 31).

Cephalic limbs—The cephalic limbs of Calymene except the
antennules were determined in 1881, and those of Triarthrus in
1895,’ and Neolenus including antennules in 1918 (pl. 31). In the
three genera the protopodites of four pairs of limbs form gnathobases
to which are attached the endopodite or jointed leg as the main stem
of the limb and an exopodite that is fairly well known for Triarthrus
and Neolenus and less so for Calymene. The character of the limbs
and their position indicate that the trilobite lived on soft food that
was pushed along to the mouth by the protopodites. No evidence
has been discovered of the existence of specialized gnathobases cap-
able of crushing or triturating hard food.

Thoracic limbs.—The thoracic limbs of the species of trilobite with
which they have been found have a large protopodite and a strong,
relatively large and long endopodite that formed a powerful walking
leg of six joints and a short terminal claw; the legs vary somewhat
in size in the several species, but all were adapted to the needs of the
animal both when walking and when forcing its way through soft
mud and sand in search of food. In addition to the endopodite an
exopodite is known to have been present in the thoracic limbs of
Calymene, Ceraurus, Neolenus, Kootenia, Triarthrus, Trinucleus,
and Odontopleura. The spiral exopodites are found in Calymene,

* Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, 1881, pl. VI, fig. 1.
* American Geol., Vol. XV, 1895 (February), pl. V, figs. 8-11.

NO. 4 APPENDAGES OF TRILOBITES 161

Ceraurus, and Odontopleura; the flabelliform types in Neolenus and
Kootenta; the setiferous plumes of Tviarthrus appear to have
been capable of service as swimming organs, also of functioning
as branchiz.

It is probable that flat, more or less setiferous epipodites occurred
on the protopodites of the limbs of most if not all trilobites, but we
know them with certainty only on Neolenus, Calymene, and Ceraurus,
and somewhat doubtfully in Triarthrus. They attain their greatest
development in Neolenus, and the same is true of the small, flat lobes
tentatively referred to as exites. The several types of thoracic limbs
as now known are illustrated by diagrammatic drawings which are
reproduced by figures 4-7, plate 35.

Pygsdial limbs—The limbs beneath the pygidium appear to be
essentially the same as those of the thoracic region as far as the
endopodite is concerned and usually the same is true of the exopodite,
the known exception being in Triarthrus where the many jointed
setiferous arm of the exopodite appears to resolve itself into a series
of minute lobes that are transverse to the axis of the limb and look
- like the exites of a phyllopod limb.

Summary.—The appendages may be summarized as follows:
Cephalic: —

1. Antennules—Uniramose, slender, many jointed, and attached
to the ventral integument of the cephalon about midway
of the glabella.

2. Antenne.—Represented by the anterior pair of cephalic
limbs which are posterior to the opening of the mouth.

3. Mandibles—Represented by the second pair of cephalic
limbs.

4. Maxillula—Represented by the third pair of cephalic limbs.

5. Mavilla—Represented by the fourth pair of cephalic limbs.

Thoracic: A pair of biramous limbs to each segment or somite of the
thorax, each limb consisting of a fused coxopodite and baso-
podite forming a protopodite; an attached, six-jointed endopo-
dite or leg with a terminal spine or spines, one of which is
usually in the form of a slightly curved claw; an exopodite that
may or may not be jointed and which is attached to the distal
end of the protopodite; one or more flabelliform epipodites
attached to the distal part of the endopodite and in one instance

(Neolenus) one or more exites (attached to the anterior side of

the protopodite ?).

162 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Abdominal: No abdominal appendages are differentiated from those
of the thorax by their structure. Those referred to as such are
the limbs beneath the pygidium which are similar in structure to
those beneath the thorax. A pair of pygidial limbs occur for
each segment of the pygidium and the posterior ones may show
traces of a more primitive structure.

Caudal rami: Known only for Neolenus. Long, slender, many
jointed, uniramous and attached to the ventral integument at the
posterior end of the pygidium. The caudal rami are not con-
sidered to represent true limbs, although in Neolenus they are
quite similar in appearance to the antennules and are attached to
the ventral integument. They may represent the appendages of
the anal segment.

PosITION OF THE LIMBS

When I took up the question of the restoration of the ventral
appendages of Neolenus I decided to study first the form and arrange-
ment of the appendages of the Branchiopoda, and following that the
Malacostraca, as I considered the trilobite to be a form intermediate
in its development between the Branchiopoda and the lower Mala-
costraca, as represented by the Phyllocarida, Syncarida, and Mysi-
dacea. The appendages of the trilobite genera Triarthrus, Calymene,
Ceraurus, and Isotelus were then examined with a view of ascertain-
ing 1f possible their form and arrangement when the animal was
living. These studies and comparisons led me to the conclusion that
the limbs of the trilobites had essentially a similar arrangement as
those of the Branchiopoda, that the cephalic appendages were less
specialized, and that the form of the protopodite was that of a
flattened joint projecting inward and forward toward the median
line and providing at its distal end support for the endopodite or
jointed leg and a varying form of exopodite, and epipodites if
present.

I then examined some large specimens of Apus lucasanus Packard
in which, looking on the ventral surface, the protopodites of the
thoracic limbs extend obliquely forward from each side towards
the median line at an average angle of 30°, and present the narrow
ventral surface of the protopodite and its anteriorly sloping surface
which almost passes beneath the next anterior limb when viewed
from above as the animal is lying on its back. This gives the effect
of broad, closely arranged thoracic limbs when actually they are
narrow and deep. I next gradually pressed a specimen out flat
between strong glass plates, so that it was possible to see just what

NO. 4 APPENDAGES OF TRILOBITES 163

happened to it from the beginning of the application of the flattening
process until it was completely flattened out. The result was that
the protopodite and connecting joints of the limbs were seen to
change from pointing forward with the narrow ventral edge upper-
most to a position where they were directly transverse or pointing
backward and with the flat side of the joints pushed over so as to lie
on the plane of the dorsal shield, a position usually found in the limbs
of the fossil trilobite.

This experiment was repeated many times with the same result.
If we now consider that the larger number of trilobites which have
been found with the appendages attached were lying on their backs
and that the silt settled down directly on the appendages and as the
weight increased the appendages were pressed down on the dorsal
shield and flattened out very much in the same manner as Apus with
the glass plates, it is extremely probable that the limbs were pressed
out of position and often pushed out beyond the edges of the dorsal
shield. I also submitted a number of small specimens of Limulus
polyphemus to pressure between glass plates and found that the flat
proximal joints of their cephalic legs assumed nearly the same posi-
tion as the legs of the fossil trilobite and pointed more or less
backward.

The position of the limbs in the fossil specimens is clearly indi-
cated for Neolenus on plates 15, 17-19, where the protopodite and
endopodite (leg) extend outward and backward from the median
axis of the dorsal shield ; the exopodites extend outward and forward,
plates 21-23; the cephalic limbs extend outward and forward as in
plate 16. Although pressed flat on the shale and more or less forced
away from their original position in relation to their points of attach-
ment to the ventral integument, the limbs are probably in a more
natural position than those of Jsotelus and Triarthrus.

The limbs of Jsotelus (pl. 25) slope forward in such a manner as to
indicate that the protopodites have all been forced over and swung
around so as to point backward towards the central axis and forward
and outward or almost the reverse of their position when living ; the
endopodites are nearer their probable normal position, but still slope
too much forward.

The limbs of Triarthrus have the axis of their protopodites sloping
inward and backward as in Jsotelus, with the endopodite and exopo-
dite extending forward in a natural position.

The conclusion drawn from the study of the limbs of the fossils
and recent crustaceans is that the normal position of the protopodites

164 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of the trilobite was that indicated in the restorations of Neolenus
(pl. 31), Triarthrus (pl. 32), Calymene (pl. 33), also that the flat
protopodites and adjoining joints of the endopodite (leg) were
vertical or nearly so to the plane of the ventral surface and dorsal
shield, and when viewed from directly above when the animal was
lying on its dorsal surface would show only the thin edge of the
joints as shown in the restorations, plates 31-33. The deep or broad
side of the limbs is seen only on a side view as shown by the trans-
verse sections on plate 34. It is probable that Beecher was misled
by the appearance of the appendages of Triarthrus in the fossil state
in making his restoration of the ventral surface and appendages of
T. becki as he represents the limbs from the proximal end of the pro-
topodite to the distal joint of the endopodite as lying on their side,
and also has the protopodite pointing obliquely backward.

Respiration of the trilobite—Walcott assumed that the function
of respiration in Calymene and Ceraurus was performed by the spiral
exopodites and setiferous epipodites." Beecher wrote of the probable
respiratory apparatus of Triarthrus and Trinucleus:’*

No traces of any special organs for this purpose have been found in this
genus, and their former existence is very doubtful, especially in view of the
perfection of details preserved in various parts of the animal.

‘The fringes on the exopodites in Triarthrus and Trinucleus are made up of
narrow, oblique, lamellar elements becoming filiform at the ends. Thus, they
presented a large surface to the external medium, and partook of the nature
of gills.

Beecher quotes Gegenbaur as follows: *

The functions of respiration and of locomotion are often so closely united
that it is difficult to say whether certain forms of these appendages should be
regarded as gills, or feet, or both combined. [Elements of Comparative
Anatomy, English edition (Bell and Lankester), p. 241.]

If the flat, epipodite-like lobes illustrated in figure 19, plate 30, are
what they appear to be they would have served as gills.

Neolenus has an elaborate respiratory system if we consider the
exopodite and the epipodites (pl. 35, fig. 4) as gills. In this species
the protopodite and endopodite of the limbs were so strong that it is
not probable that the test covering them functioned in respiration.

There is no doubt of the presence in the trilobite of well-developed
and specialized organs of respiration comparable with those of the
Malacostraca, such as the Nebaliacea, Anaspidacea, and Mysidacea.

* Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, 1881, pp. 207, 208.
* American Jour. Sci., 4th ser., Vol. I, 1896, p. 255.
* Idem.

NO. 4 APPENDAGES OF TRILOBITES 165

Restoration of ventral appendages.—tThe restorations of the ventral
surface and appendages of Neolenus, Triarthrus, and Calymene are
undertaken in order to present in graphic form these crustaceans as
I conceive they appeared when living. It was with great hesitancy
that the broad, short protopodite as I drew it in 1881 * was abandoned
and the narrow, deep, elongate protopodite substituted. The limbs
of Neolenus, however, clearly had a deep, narrow protopodite and a
similar form evidently prevailed in the first three joints of the
endopodite. A study of specimens of the limbs of Triarthrus led
to the same result and with these two in mind the sections of the
limbs of Calymene and Ceraurus were found to be capable of a
similar interpretation as far as the protopodites and to a limited
extent the proximal joints of the endopodite were concerned.
Another line of supporting evidence is given by the tracks, trails,
and burrows made by trilobites on and in the muds and sands of
Cambrian time. The sharp, deep, clearly lined imprints (pls. 38-40)
could only have been made by a strong limb with a narrow and deep
protopodite and endopodite. With this form of limb in mind the
restorations are made as though looking directly down on the ventral
surface, so as to show the narrow side of the limbs and a little of their
sides for Neolenus, plate 31, Triarthrus, plate 32, and Calymene,
plate 33. The exopodites of the three species were quite unlike and
they have been represented so as to give some conception of their
form by turning them partially over on their side. Their position
in the transverse sections (pl. 34) is more nearly natural than as they
are represented on plates 31-33.

I have planned for twenty years to redraw my restoration of
Calymene of 1881, but it was not until the material representing
Neolenus was studied that I felt that the restoration could be under-
taken with a prospect of improving on the first attempt. After work-
ing out Neolenus and Calymene I studied Beecher’s restoration of
Triarthrus and a number of original specimens and made a sketch
from which the restoration on plate 32 was drawn. Sketches of the
transverse sections were also made with a view of obtaining side
views of the limbs; a third sketch is a diagrammatic outline of the
limb of each species with all known appendages attached to the pro-
topodite so as to clearly distinguish them.

* Bull. Museum Comp. Zool., Harvard Coll., Vol. VIII, 1881, pl. VI, fig. 1.
* Idem, pl. VI, fig. 1. Smithsonian Misc. Coll., Vol. 57, 1912, p. 192.

166 SMITHSONIAN MISCELLANEOUS COLLECTIONS © VOL. 67

The sketches were turned over to Mr. Clarence R. Shoemaker, of
the U. S. National Museum, as the base for the drawings reproduced
on plates 31-34, with the request that he would, from his knowledge
of the appendages of the Crustacea, give the restorations as natural
an appearance as possible.

The restorations may be of service to the student of recent and
fossil crustacea and also serve as a stimulus to further research in
order that with new material and a different point of view more
satisfactory results may be obtained by the future student. The
restorations of the thoracic limbs are so fundamental I will mention
them more fully.

Restoration of thoracic limbs —As far as known the thoracic limb
of Neolenus, Isotelus, Triarthrus, Ceraurus, and Calymene has a
large protopodite to which the leg (endopodite), exopodite, and
when present the epipodite or epipodites are attached. This large
protopodite is presumably formed of a basopodite and coxopodite so
closely fused that the line of jointing has disappeared.

Neolenus.—Represented by Neolenus serratus (Rominger), from
the Middle Cambrian. This is the most complex limb thus far
known among the trilobites. It has (pl. 35, fig. 4) a true ambula-
tory leg (endopodite) attached to a large protopodite that served
also as a gnathobase and as the base for a large setiferous exopo-
dite and large and small lobe-shaped epipodites, and on the anterior
series of limbs at least one or two small, flat endites. This limb
is much like the anterior thoracic limb of Anaspides tasmanie
(pl. 35, fig. 1) and has the same elements in it as the first thoracic
limb of Paranaspides (pl. 35, fig. 3). The exopodite in the first
thoracic limb of Anaspides is a simple unjointed rod, but on the
second limb it is jointed, somewhat setiferous, and antenne-like in
the outer portion. The endites on the inner side of the coxopodite of
the first thoracic limb serve as gnathobases, but they are not present
on the posterior limbs. The flat, lobe-like epipodites are essentially
similar in all the genera of the Anaspidacea. Their position is shown
on plate 35.

Calymene (pl. 35, fig. 6).—Represented by C. senaria Conrad of
the Trenton formation of the Ordovician. This limb is nearly as
complex as that of Neolenus as it has an endopodite, exopodite, and
an epipodite, but in its simple bispiral exopodite and small epipodite ~
it does not appear to be as highly developed a limb.

Ceraurus (pl. 35, fig. 7)—Represented by Ceraurus pleurexan-
themus Green of the Ordovician. As far as known the limb of this
species is essentially similar to that of Calymene.

NO. 4 APPENDAGES OF TRILOBITES 167

Triarthrus (pl. 35, fig. 5). —Represented by Triarthrus becki Green
of the Utica shale of the Ordovician. The anterior thoracic limbs of
Triarthrus have the elements of the limb of Neolenus, Calymene, and
Ceraurus, and may be compared with them except as to the details
of the exopodite and epipodite. The more posterior limbs show
flattened and transversely elongate joints. (pl. 34, figs. 6 and 7) which
Beecher compares with the large endites of the phyllopodan limb.
In the restorations, plate 32, I have given the limb from beneath the
pygidium nearly the same form as the thoracic limb, basing it on the
specimens available for study in the collections of the National
Museum. The transverse phyllopodan-like joints of the exopodite
of the limbs of the posterior portions of the animal beneath the
pygidium are not represented in the diagrammatic sections (See pl.
29, figs. 4, 5, 8, 11).

The longitudinal restorations of the thoracic limbs (pl. 35) were
drawn in order to clearly indicate the various elements entering into
the structure of the limb. These should be compared with the side
views of the limbs in the transverse sections (pl. 34) and those of
the restorations of the ventral side of Neolenus, Triarthrus, and
Calymene (pls. 31-33).

Comparison with crustaceans—Early authors (1750-1843) com-
pared the dorsal shield of the trilobite with various crustaceans,
especially Apus and Limulus,’ and when traces of appendages began
to be discovered these comparisons were continued* (1870-1881).
Bernard, as the result of a very comprehensive study, felt confident
that the trilobites may take a firm place at the root of the crustacean
system with the existing Apus as their nearest ally.’

He concluded * that—

Apus, on account of its richer segmentation, the absence of pleurae on the
trunk-segments, and its more membraneots parapodia-like limbs, must be as-
sumed to lie in the direct line upwards from the original annelidian ancestor
toward the modern crustacea. The trilobites then must have branched off
laterally from this line either once or more than once, in times anterior to the
primitive Apus, as forms specialized for creeping under the protection of a
hard imbricated carapace.

1See Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, 1881, pp. 193-195.

* Idem, pp. 195-197.

® Nature, Vol. 48, 1803, p. 582. Quart. Jour. Geol. Soc. London, Vol. 50, 1894,
pp. 411-432, arid Vol. 51, 1895, pp. 352-350.

4 The Systematic Position of the Trilobites, Idem, 1894, Pt. I, pp. 429-430.

168 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

In 1895, with the new evidence afforded by the trilobite Triarthrus
becki, he concluded * that—

The trilobites, therefore (as exemplified by Triarthrus), in spite of their
extremely primitive mouth-formula, do not stand in the direct line of descent
of the Crustacea, but are lateral offshoots, specialized for a creeping manner
of life.

The discovery of the limbs of Triarthrus led Walcott to abandon
the view (held in 1881) that the trilobite was closely allied to
Limulus’ in favor of its being a crustacean that was neither a “ true
Entomostracan or Malacostracan nor was it a lineal descendant from
either, but was probably a descendant from a common ancestral
type” * of all three.

Two general facts led me in 1894 to think that the modern
crustacean is descendant from the Phyllopod branch of the Branchi-
opoda and the Trilobita from a distinct branch.“ 1st. The Trilobita
branch exhausted its vital energy in Paleozoic time and disappeared.
2d. The Phyllopod branch developed slowly until after the Trilobita
passed its maximum and then began its great differentiation that in
its descendants approaches culmination in recent times.

When the trilobite and phyllopod diverged from their common
crustacean ancestor, the trilobite began to differentiate and to use
its initial vital energy in developing new species, genera and families.
Probably two thousand species and one hundred or more genera are
known from Paleozoic strata. With this great differentiation the
initial vital energy was exhausted and the Trilobita disappeared at
the close of Paleozoic time without leaving direct descendants.

The Branchiopoda, including the Ostracoda, Copepoda, and Cirri-
pedia developed steadily during Paleozoic and subsequent geologic
time until to-day their descendants form the subclasses Branchiopoda
and Malacostraca, each of which is equivalent to the subclass Trilo-
bita of Paleozoic time. Springing from a common crustacean base
the three groups have many features in common, and in details of
structure of the limbs many striking resemblances occur. It does
not impress me that trilobites were true Branchiopodans or Mala-
costracans ; they have certain characteristics in common, but these are
not necessarily the result of lineal descent one from the other, but
are the result of descent from a common ancestral crustacean type of

* Quart. Jour. Geol. Soc. London, Vol. 51, 1895, Pt. 2, p. 356.

2 Bull. Mus. Comp. Zool., Harvard Coll., Vol. VIII, 1881, pp. 209-211.

® Proc. Biol. Soc. Washington, Vol. IX, 1894, p. 94.

*This view is only confirmatory of the result of the profound study of the
Apodide by Bernard (The Apodide, Nature Series, 1892).

NO. 4 APPENDAGES OF TRILOBITES 169

pre-Cambrian time that lived in the pelagic fauna in which all the
earlier types of life were probably developed* and from which, as
time passed on, additions were made to the paleontologic record of
the geologic series of formations. We know that Phyllopods, Ostra-
cods and Trilobites were clearly differentiated in lower Cambrian
time. ;

Beecher compared the trilobite with the phyllopods and concludes
that points of likeness may be established with almost every order of
Crustacea, showing chiefly the relationship between the trilobite and
the ancestors of modern Crustacea.” He has well summed up the
evidence in favor of the trilobites being considered true crustaceans
rather than allied with the Arachnids.* Also in his classical memoir
on the “ Natural Classification of the Trilobites ” he states the claim
of the trilobite to a position as a subclass of the Crustacea equivalent
to the subclass Entomostraca and the third subclass Malacostraca.
He concludes : *

In nearly every particular the trilobite is very primitive, and closely agrees
with the theoretical crustacean ancestor. Its affinities are with both the
other subclasses, especially their lower orders, but its position is not inter-
mediate. }

I have neither the time nor space in which to review further the
literature on the trilobites. It is too voluminous ; the student will find
the list of works given in the Zittel-Eastman Text-book of Paleon-
tology, 1913, Vol. I, pp. 692-694, to be very helpful, and there is also
there a valuable discussion of the trilobite by Beecher as revised by
Raymond.

In connection with the study of Neolenus I have had occasion to
compare the general arrangement of trilobite limbs with those of the
order Notostraca (Apus, etc.) and to compare its limbs with those of
the Malacostracan order Anaspidacea.

Apus.—tThe trilobite is clearly not a Branchiopod. Beecher con-
‘sidered that the supposed phyllopod-like legs (endopodites) beneath
the pygidium of Triarthrus brought the trilobites close to Apus, but
if my view is correct, that the endopodites are normal beneath the
pygidium and that it is the exopodite that has the primitive lobe-like

*See Brooks’ beautiful memoir on Salpa, with its suggestive theory of the
origin of the bottom faunas of the ocean and the early geologic faunas. The
Genus Salpa, Memoirs from the Biological Laboratory of The Johns Hopkins
University, II, 1893, pp. 140-177.

? American Geol., Vol. XV, 1895, p. 90.

® Text-Book of Palaeontology, Zittel-Eastman, 1900, p. 622.

“American Jour. Sci., 4th ser., Vol. III, 1897, p. 93.

170 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

joints, the relation to Apus is weakened as the exopodite is very much
more variable in the trilobite than the endopodite.

The more simple oral appendages of the trilobite compared with
those of Apus (Branchiopoda), which has reduced and considerably
specialized mouth parts, indicates that they are more primitive than
those of Apus, but the highly developed thoracic limbs of the trilobite
and its dorsal shield point to Apus as somewhat nearer the primitive
crustacean type.

The typical trunk limb of the branchiopod includes the primary
elements of the limb of the trilobite, but while the trilobite limb
undoubtedly passed through the branchiopod stage it was long before
Cambrian time and before the life of the oldest trilobite we now
know. Beecher thought that he had found evidence of a branchiopod
limb in the limbs beneath the pygidium in Triarthrus, but as men-
tioned above the evidence for this view may be otherwise interpreted.
The series of setiferous lobes on the proximal joint (protopodite) of
the limbs of Apus, extending inward toward the median line of the
ventral surface of the body and which function as gnathobases, is
represented in the trilobite by the long protopodite of the limbs with
its setiferous proximal end and ventral margin.

Marrella.—With the Middle Cambrian Marrella splendens Walcott’
the trilobite has several characters in common. These include (a)
sessile eyes, (b) a large hypostoma with the proximal joints of the
cephalic limbs assembled at its posterior end or beneath it, (c) a pair
of biramose limbs for each trunk segment, and (d) expansion of the
joints of the posterior thoracic legs (endopodites).

Its more specialized mouth parts, and absence of gnathobases on
the thoracic limbs, indicate less primitive characters, while its cara-
pace and an almost total absence of an abdominal section or pygidium
points to it as a primitive form possibly ranking in development
between A pus and the trilobite.

Anaspidacea.—The most striking instance of similarity of the
thoracic limbs of a trilobite and those of a recent crustacean is that of
the thoracic limbs of Neolenus which strongly suggest those of the
Malacostracan genus Anaspides, a crustacean of the order Syn-
carida, found in a fresh-water pool in Tasmania, New Zealand. The
resemblance is shown by the presence in both of a strong ambulatory
jointed leg (endopodite), a jointed setiferous exopodite, and two

1 Smithsonian Misc. Coll., Vol. 57, 1910, p. 193, pls. 25, 26.
1On the genus Anaspides, W. T. Calman, Trans. Royal Soc. Edinburgh,
Vol. 38, Pt. 4, 1896, p. 791, pl. 2, fig. 12.

NO. 4 APPENDAGES OF TRILOBITES 7

jointed flabelliform epipodites attached to the proximal joints (coxop-
odite and basopodite) of the limb. Whether or not the plate-like
lobes shown beside the median lobe of the dorsal shield in figures 3
and 4, plate 20, of Neolenus can be compared with the internal lobes

ANASPIDES TASMANIZ G. M. Thomson

Fic. I (X 3.5).—Side view of male illustrated here to show thoracic legs
with exopodites and epipodial lamellz. This species is without dorsal shield.
(After Calman, Trans. Royal Soc. Edinburgh, Vol. XXXVIII, pt. iv, 1806,

Ole De 12s Ts)

KOONUNGA CURSOR Sayce
Fic. 2 (X 37).—Anterior part of the animal, showing character of first
thoracic limb with its leg (endopodite), exopodite (ex), and epipodites (ep).
(After Sayce, Trans. Linnean Soc. London, 2d ser., Zool., Vol. XI, pt. 1, 1908,
pit. fig: 3.)

172 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of the coxa of the maxilliped of Anaspides’ is not readily determined,
but it is very suggestive and not improbable (pl. 35, figs. 1-3). The
exopodite of the thoracic limb of Anaspides (text fig. 1) recalls in its
jointed structure the exopodite of Triarthrus, but the exopodite of
Koonunga (text fig. 2), although jointed is quite unlike it, and the
exopodite of Paranaspides (text fig. 3) is slender, closely jointed and
setiferous, and much like that of Anaspides.

Another form closely allied to Anaspides is Koonunga Sayce. It
differs from Anaspides in having a sessile eye as in all trilobites
with eyes, in details of several of the appendages, the mouth parts,
and in having the anterior thoracic segment fused to the cephalon.
The thoracic leg is essentially the same as that of Anaspides (pl. 35,
fig. 2). Mr. Sayce considers Koonunga the most primitive Edri-
ophthalmatan known.

PARANASPIDES LACUSTRIS Smith

Fic. 3 (X 4).—Thoracic limbs with leg, epipodites and exopodite.
(After Smith.)

The first thoracic limb of Paranaspides Smith* has a jointed leg
(endopodite), a simple unjointed exopodite, two epipodites, and two
simple flat lobes (exites) attached to the coxopodite (See pl. 35, fig.
3). The latter are of interest to us as they correspond in form and
probably position to the flat, plate-like lobes (exites) found in con-
nection with the thoracic limb of Neolenus. A feature to be con-
sidered is that these flat lobes-occur only on the anterior or first
thoracic pair of legs in the Anaspides while they are known to be

*On the genus Anaspides, W. T. Calman, Trans. Royal Soc. Edinburgh, Vol.
38, Pt. 4, 1806, p. 791, pl. 2, fig. 12.

* Trans. Linnean Soc. London, 2d ser., Zool., Vol. 11, Pt. 1, 1908, pp. 1-16,
isn:

*Proc. Royal Soc. London, Ser. B, Vol. 80, 1908, p. 470, text fig. No. 6, p. 171.

NO. 4 APPENDAGES OF TRILOBITES 173

present in a position to indicate that they were associated with several
of the anterior thoracic legs of Neolenus.

The thoracic limbs of the trilobite differ from those of the Anaspi-
dacea by having the coxopodite and basopodite of the latter fused in a
strong protopodite, but it is quite evident that the latter have char-
acters in their thoracic limbs that were present in the trilobite. In
other respects the species of the Anaspidacea are quite unlike the
trilobite as now known to us.

Nebaliacea.—The thoracic limb of Nebalia with its jointed leg-like
endopodite, lobe-like exopodite and epipodite is much like that of
Neolenus except in the development of the basopodite. In its more
specialized cephalic limbs and separation of the thoracic limbs into
two distinct tagmata of eight pairs of thoracic limbs and the
abdominal section of seven somites, Nebalia is less primitive than
the trilobite.

Cyamus.—An examination of the spiral branchiz of the parasitic
crustacean Cyamus scammoni Dall shows them to be formed of a
slender, strong, tapering tube that may be a complete spiral as shown
by figure 9, plate 28, or it may be straightened out near the base and
irregularly coiled towards the distal end. If the spiral of an alcoholic
specimen is bent over or pulled out of shape without breaking, it at
once springs back to its original form when released. The spirals
of Cyamus are apparently attached to the ventral surface directly,
but not on the same segment with the jointed leg. As Cyamus is a
highly modified parasitic crustacean it is probable (as suggested by
Mr. C. R. Shoemaker) that the coxopodite of the leg that has been
lost in the changes incident to a parasitic life has become fused with
the segment and thus the spiral branchiz have become apparently
attached to the ventral surface of the segment. They are attached
at the same point of the pleural part of the segment as the legs on the
adjoining segments. The spiral branchiz are introduced as they
serve to explain the spirals of the exopodites of Calymene and
Ceraurus, also as an illustration of the survival of an unusual char-
acter of the trilobite or a recurrence of the same form in a modern
crustacean.

Conclusion—Many further comparisons of parts might be made
with other modern crustaceans (e. g., the Mysidacea, Euphausiacea,
some of the “ Schizopods ”’), but they would only go to prove that the
trilobite is a primitive crustacean far back on the line of descent from

174 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the original crustacean type which existed in pre-Cambrian or
Lipalian time.’
TRACKS OF TRILOBITES

When writing of the tracks occurring on the Upper Cambrian
Potsdam sandstone of Canada and New York in 1912, I said:*

If we picture in our imagination a trilobite with a series of twelve pairs of
legs posterior to the cephalon (figs. 1 and 2), and five pairs of cephalic legs,
walking on the smooth or rippled surface of fine wet sand exposed at low tide,
I think we can readily explain the Protichnites tracks on the Potsdam sand-
stone. Such a series of feet would make varied and complex series of tracks
that would differ in depth, definition and details of grouping with the varying
degree of consistency and hardness of the surface over which the animal was
traveling and its method of moving. I have fine trilobite trails made on the
surface of sandy mud that show the imprint of a considerable portion of the
legs. Ona hard surface the animal touched only the extremities of the legs,
but on a muddy surface the terminal joint would sink in and other joints would
leave an impression.

The trifid imprint resulted from the impress of the end of the terminal
joint of the trilobite’s leg with its three movable spines.

Some of the tracks referred to above are illustrated on plate 42,
and on plates 37, 38, 41, a series of trilobite tracks and trails from the
Middle Cambrian sandstones of the Grand Canyon of the Colorado
River. The latter show the impression of the distal joints and some
the entire length of the leg as the surface in places was less resistant
and the leg sank deeper into it. The series of tracks and burrows
also clearly indicate that the trilobite was the animal that made the
trails, burrows, and wallows that gave rise to the casts that have
been largely described by authors under the generic term Cruziana
d’Orbigny.’

The size and depth of the trails left by the trilobite prove that their
legs were long, strong, and attached to a large protopodite. When
the animal was pushing its way through a soft surface of sand or fine
muddy sediment in search of food (Annelids, etc.), the legs appear to
have bunched together in groups of two, three or more, and slowly ~
crowded the animal forward (pl. 38, figs. 3, 4; pl. 39, pl. 40). That
it was annelids the trilobite was seeking is indicated by the presence
in the sandstone or shale of large numbers of annelid borings and
casts of trails, some of which follow along the furrow made by the

1Smithsonian Misc. Coll., Vol. 57, 1910, p. 14 (footnote).

* Idem, 1912, No. 9, p. 278.

®> See Delgado for description and illustrations. Estudo Sobre os Bilobites
de Portugal, Acad. Sci. Lisbon, 4to, 1886.

NO. 4 APPENDAGES OF TRILOBITES 175

trilobite (pl. 37, fig. 3), while others are beneath it or cross at various
angles. One of the small slabs of annelid trails and casts of borings
is illustrated on plate 42, and there is a large series of them in the
collections of the United States National Museum.

I will not give a detailed description of the tracks and trails as the
illustrations tell the story of the almost endless variation caused by
the varying conditions under which they were made. We know
something now of the variation in size, form, and length of trilobites’
limbs, and it is evident from the tracks and trails that there were
many other variations of which nothing is known. When experi-
menting with the common rock crab of the New England coast, I
found that by causing the same crab to creep, run, or wallow on and
in sediments of varying material, hardness, and consistency, many
kinds of tracks and trails could be produced, and the same was true
with the common “Horse Shoe” crab (Limulus) of the Florida
shore. If we had a living crustacean with the same type of protop-
odite, endopodite and exopodites, and dorsal shield that the trilobite
has, it would be quite possible to largely reproduce the trails and
tracks illustrated on plates 37-42.

Just how the trilobite used its numerous limbs when pushing
through the mud or sand it is difficult to imagine. The motion must
have been very slow and probably there was a general irregularity
of movement of the limbs when the more complicated trails were
made. ‘This is indicated by figure 6, plate 37; figure 3, plate 38;
figures 1-4, plate 39; figures 1-5, plate 40. Such trails as that of
figure 2, plate 41, are less complicated than the trail represented by
figure I, plate 39. There is no animal known from the rocks on which
the tracks and trails occur but the trilobite that could have made
them.

The trilobites that may have made the trails on the sands and muds
of Middle Cambrian time include species of the genera Agnostus,
Eodiscus, Ptychoparia, Dolichometopus, Bathyuriscus, Asaphiscus,
Neolenus, etc. These give a wide variation in size, and undoubtedly
in ventral appendages and the same is true of the trilobites of the
Lower and Upper Cambrian, Ordovician, Silurian, and Devonian
time. Some future student of the trails and tracks found on Paleozoic
rocks should make great collections and also conduct many experi-
ments with recent crustaceans in the making of trails and tracks
under all possible conditions. Most interesting results will be secured
by a careful, patient, thorough worker.

176 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

GENERAL SUMMARY

At the risk of repetition of statements made in this paper and by
authors I will give a brief summary of the structure of the trilobite
that may possibly be of service to the teacher, and student, of recent
and fossil crustacea.

Dorsal shield—All known trilobites had a more or less chitinous
shield or carapace which was thick and strong in the Illznidz, etc., or
thin and delicate in the Mesonacide, Olenellus, etc. As yet no forms
have been found that were without a complete dorsal shield, but it is
probable that such existed in pre-Cambrian time when the trilobite
was diverging from its primitive crustacean ancestor. Naked
phyllopod crustaceans lived in Middle Cambrian time and left their
record on the Burgess shale,’ so it is possible that such can be pre-
served. One trilobitic-like form, Nathorstia,* had a very delicate
dorsal shield, and possibly others existed in earlier Cambrian time
that will add to the story of the evolution of the carapace on
structure of the ventral surface and appendages.

The subclass Trilobita may be defined, after Raymond in Zittel’s
Text-book,’ modified to meet data afforded by Neolenus, as follows:

Marine Crustacea, with a variable number of metameres (segments) ; body
covered with a hard dorsal shield or crust, longitudinally trilobate into the
defined axis and pleura; cephalon, thorax and abdomen distinct. Cephalon
covered with a shield composed of a primitively pentamerous middle piece,
the cranidium, and two side pieces, or free cheeks, which may be separate or
united in front, and carry the compound sessile eyes when present; cephalic
appendages pediform, consisting of five pairs of limbs, all biramous, and
functioning as ambulatory and oral organs, except the simple antennules, which
are purely sensory. Upper lip forming a well-developed hypostoma; under
lip (epistoma) present. Segments of the thorax movable upon one another,
varying in number from two to twenty-nine. Abdominal segments variable in
number, and fused to form a caudal shield. Ventral integument a thin un-
calcified membrane, divided into pleurosternites and mesosternites connected
segmentally by an interarticulate membrane. Mesosternites usually with five
longitudinal ridges, a median one with two oblique extending obliquely forward
on each side (the spaces thus formed indicate attachment of ventral muscles).
All segments, thoracic and abdominal, carry a pair of jointed biramous limbs.
All limbs have their proximal elements forming gnathobases, which become
organs of manducation on the head. Respiration integumental and by bran-

* Smithsonian Misc. Coll., Vol. 57, 1912, pp. 157-170, pl. 27, fig. 6; pl. 28, fig. 1.
Opabinia.

7Idem, pp. 194-195, pl. 28, fig. 2.

* Zittel-Eastman, Paleontology, 1913, Revised by Raymond, pp. 692-694.

NO. 4 APPENDAGES OF TRILOBITES 1.

chial fringes on the exopodites, epipodites, and exites. Development proceed-
ing from a protonauplius form, the protaspis, by the progressive addition of
segments at successive moults. ,

Intestinal canal——Of the internal organs only the intestinal canal
is known. This, starting at the mouth, curves upward, and extends
beneath the median lobe of the dorsal shield the entire length of the
body, terminating at the anal opening beneath the last segment of the
pygidium. There were probably hepatic ceca opening into the
anterior end, but as yet none have been seen, although they are present
in the Branchiopod genus Burgessia, which is associated with Neo-
lenus in the Burgess shale.’

The appendages may be summarized as follows:
Cephalic:

1. Antennules——Uniramose, slender, many jointed, and attached
to the ventral integument of the cephalon about midway
of the glabella.

2. Antenne—Represented by the anterior pair of cephalic
limbs which are posterior to the opening of the mouth.

3. Mandibles—Represented by the second pair of cephalic limbs.

4. Maxillula.—Represented by the third pair of cephalic limbs.

5. Maxilla—Represented by the fourth pair of cephalic limbs.

Thoracic: A pair of biramous limbs to each segment or somite of the
thorax, each limb consisting of a fused coxopodite and baso-
podite forming a protopodite ; an attached six-jointed endopodite
or leg with terminal spines, one of which is usually in the form
of a slightly curved claw; an exopodite that may or may not be
jointed and which is attached to the distal end of the protopodite ;
one or more flabelliform epipodites attached to the distal part
of the endopodite and in one instance (Neolenus) one or more
exites (attached to the anterior side of the endopodite ?).

Abdominal: No abdominal appendages are differentiated from those
of the thorax by their structure. Those referred to as such are
the limbs beneath the pygidium which are similar in structure
to those beneath the thorax. A pair of pygidial limbs occur for
each segment of the pygidium and the posterior ones may show
traces of a more primitive structure.

1Smithsonian Misc. Coll., Vol. 57, 1912, pp. 177-180, pl. 27, figs. 1-3; pl. 30,
figs. 3, 4.

178 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Caudal rami: Known only for Neolenus. Long, slender, many
jointed, uniramous and attached to the ventral integument at
the posterior end of the pygidium. The caudal rami are not con-
sidered to represent true limbs, although in Neolenus they are
quite similar in appearance and seem to be attached to the
ventral integument as though they represented the appendages
of the anal segment.

Manner of life —The trilobite was a marine crustacean that lived
in shallow seas, bays, sounds and inlets, and sometimes deeper waters.
In its younger stages of growth a free moving and swimming animal,
it later became a half-burrowing, crawling, and sometimes swimming
animal and moving at times with the flow of the tides and prevailing
currents. Much of its life must have been spent searching for food
in the mud and silt after its younger free swimming days had passed.

Its spawning habit was presumably much like that of Limulus.
Eggs have been found both within and free from the body, and a
younger stage of growth (protonauplius) occurs in the fossil state.
It was at home on many kinds of sea-bottom and was able to accom-
modate itself to muddy as well as clear water.

It was intensely gregarious in some localities and widely scattered
in others, depending upon local conditions, and habits of the various
species.

Respwation.—Trilobites had an ample system of respiration by
setiferous exopodites, epipodites, and exites attached to the cephalic,
thoracic, and abdominal limbs. These may be seen in the restoration
of the limbs on plates 34 and 35.

Food.—The structure of the gnathobases of the cephalic limbs
indicates soft food such as worms, minute animal life, and decom-
posed algze.

Persistence in time.—Without means of offence, and of defense
only by covering itself closely by its dorsal shield or hiding in the
mud, the trilobite persisted from far back in pre-Cambrian time to
the close of Carboniferous time. This was owing largely to its being
able to adapt itself to a varied and changing environment, and to its
great reproductive powers. Its eggs must have been brought forth in
immense numbers and in favorable localities for development.

Extinction.—The trilobite slowly developed in pre-Cambrian time,
reached its maximum in the Cambrian period, and continued on in
full tide until well into Ordovician time when the sea bottoms became
crowded with a large and varied fauna, and numerous enemies, some

NO. 4 APPENDAGES OF TRILOBITES 179

small and insidious, parasitic in nature, others large and powerful, ap-
peared, together with various types which, while not physically
antagonistic, were economically so in being better adapted to live in
the same manner under the same conditions. It kept up the struggle
but, already an ancient type, it had lost its juvenile race plasticity and
ability to modify itself to meet the new conditions, and it was there-
fore unable to adapt itself to its new environment. Never having
penetrated into fresh or other non-marine waters, or into the deep
sea, those havens of refuge where the relics of many ancient types
may still be found, the trilobite, unable to cope with the new world
in which it found itself, was consumed as food by its new enemies,
both internal and external, and at the same time subjected to over-
whelming competition, so that the individuals died off more rapidly
than they could reproduce, and the race disappeared with the close
of Paleozoic time. It persisted for many million years and left its
remains more or less abundantly through about 75,000 feet of strati-
fied rocks.

180 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 14

Neolenus*serratus*CRominger)'*.. a.< cence cee Beh ee eee ee

Fic. 1. (X 1.5.) A nearly perfect dorsal shield flattened in the shale.

It has one antennule, two caudal rami and a few legs (en-

dopodites) extending out from beneath it. The glabella of

the cephalon is crushed in as it is in all but one specimen

of the species I have seen. The median spine on each seg-

ment of the thorax and pygidium is broken off close to its

base, and usually the base and a piece of the test are broken

off with it. U. S. National Museum, Catalogue No. 65510.

The specimens illustrating Neolenus serratus (pls. 14-23) are from

locality 35k, Middle Cambrian: Burgess shale member of the

Stephen formation, on the west slope of the ridge between Mount

Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass,
above Field, British Columbia, Canada.

Kootema dawsont Walcott... 2. <...s «< 2isa sis viene 0s 0 sas s)ase ee
Fic. 2. (X2.) A somewhat broken and crushed dorsal shield that
illustrates the general character of the species. U. S.

National Museum, Catalogue No. 65511.

3. (X2.) Right side of a crushed and exfoliated dorsal shield
with portions of the thoracic legs (endopodites) and
exopodites fringed with long sete. U.S. National Museum,
Catalogue No. 65512.

This is the only specimen known to me of this species that
shows remains of the ventral appendages.
The specimens represented by figs. 2 and 3 are from locality 35k,
as given above.

131

VINSLOOM INV SNNA IOAN

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 15

NEOLENUS SERRATUS (Rominger)

No: 4° "“""" APPENDAGES‘ OF TRILOBITES © — Sr
“DESCRIPTION OF PLATE 15

; PAGE

Wenlenis serratus Beecey, Ae Lb BR ee a reads AS 126

Fic. I. (Natural . size.) Photograph of a large, partially exfoliated
Worcs dorsal shield with the antennules projecting from beneath
the cephalon, the caudal rami slightly pushed backward
from their normal position, and a fine series of the thoracic
- and abdominal legs (endopodites). Some of the legs pre-
serve the large proximal joint (protopodite). The posterior
portion of this specimen is illustrated we an enlarged figure
fon ple 17, hie. 3.

The matrix at the top of the plate econ the impres-
sion of 15 endopodites of the same character as those with
the dorsal shield. The photograph of’ this was reproduced
by me in 1912 (Smithsonian Misc. Coll., Vol. Be one Ass
fieeo Th) le

U. S. National Museum, Catalogue’ No. 58588,

The specimens illustrating Neolenus. ‘serratus are from locality

35k, Middle Cambrian: Burgess: shale member of ‘the Stephen for-
mation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile -(1.6 km.) northeast of pee Pass, above
Field, British Columbia, Canada...

182 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL,

DESCRIPTION OF PLATE 16

Neolenus serratus CRominger)). 2... 5.000008 ooce ss cee ee oslo es een
Fic. 1. (X2.) Cephalic legs (endopodites) with one plate-like ex-
opodite that probably was attached to the protopodite of the
fourth cephalic leg. The protopodite of the third leg has
numerous short spines on its inner margin that indicate that
it served as a gnathobase. U. S. National Museum, Cata-

logue No. 65513.

2. (X2.) The matrix of the specimen represented by fig. 1. Frag-
ments of the legs, etc., have exfoliated, so that the details
of the specimen and the matrix differ, and a portion of the
test of the dorsal shield is also shown on the right, lower
side. The exopodite of fig. 2 is not shown at all on fig. 1, as
its impression was removed in clearing the film of shale
over the protopodite of the third cephalic leg. U. S.
National Museum, Catalogue No. 58590.

This specimen was illustrated in 1912 (Smithsonian Misc.
Coll., Vol. 57, pl. 45, fig. 3).

3. (2.) Anterior portion of a dorsal shield with an antennule
and cephalic legs (endopodites). The distal joints of the
legs show the terminal claw and two strong, short spines.
Faint traces of the long sete attached to an exopodite are
shown near the right eye and also beside the right pleure
of the thorax. U. S. National Museum, Catalogue No.
58501.

The right side of this figure was published in 1912 (Smith-
sonian Misc. Coll., Vol. 57, pl. 45, fig. 4).

The specimens illustrating Neolenus serratus are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen for-
mation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia, Canada.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 16

Cephalic appendages of
NEOLENUS SERRATUS (Rominger)

SNOIL931109 SNO3SNV11ISZ0SIN NVINOSHLIWS

NO. 4

APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 17

MIS SREEEOLES CILOMMNMEE e005 oa a.e as ced ¥ vee tie ea cm bele creas ceewens

iG. eT

(Natural size.) A partly exfoliated specimen, showing (a)

an antennule, numerous thoracic legs (thl), and jointed
caudal rami (cr). The caudal rami have been dragged
backward, pulling with them a portion of the under edge of
the ventral lining of the body cavity. U. S. National
Museum, Catalogue No. 57656.

(Natural size.) Pygidium with the caudal rami extending out

from beneath it in their probable natural position. U. S.
National Museum, Catalogue No. 57657.

The above described figures were published in 1912
(Smithsonian Misc. Coll., Vol. 57, pl. 24, figs. 1, Ia).

(< 3.) Enlargement of the posterior portion of the dorsal

shield and appendages illustrated by fig. 1, pl. 15. U.S.
National Museum, Catalogue No. 58588. :

The basal joints (protopodites) of the limbs are not well
defined as they have been so flattened and crushed against
the inside of the dorsal shield that they have the relief of
the fused segments of the pygidium. Between the caudal
rami there are two elongate oval spots that probably repre-
sent the anal opening which was forced out of shape and
divided by pressure when the animal was buried in the
fine sediment. It looks as though the limbs and caudal rami
had been forced out from beneath the pygidium.

This figure was first published in 1913 (Text-book of
Pal., Eastman ed. of Zittel, Vol. I, fig. 1376, p. 716).

The specimens illustrating Neolenus serratus are from locality

35k, Middle Cambrian: Burgess shale member of the Stephen for-
mation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia, Canada.

183

184 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 18
_ PAGE
Neolenus serratus (Rominger) (See pl. 20, fig. 1)...........ccccccccceee 126
Fic. I. (X2.) Enlargement of the specimen illustrated by fig. 1, pl. 20.

The two anterior legs on the left side and details of the legs
showing the protopodite were worked out of the shale after
the photograph reproduced on plate 20 was taken. On the
right side back of the fourth thoracic segment, a small lobe
(epipodite) is seen with its proximal portion resting against
the protopodite of a thoracic leg. On the left side long sete
of the exopodites appear from beneath the lateral margin
of the thoracic pleura. A portion of the caudal rami pro-
jects from beneath the pygidium. The joint lines of the legs
have been darkened and the spines on the protopodites

lightened so as to bring them out in stronger relief. See -

description of this specimen on pl. 20, fig. 1, for catalogue
number.

Diagrammatic transverse section at about the fourth thoracic

segment. This is based on the restoration illustrated on
plate 31. The lettering is as follows:

d.s.= dorsal shield. exi. = exite.
en. = endopodite. int. = intestinal canal.
ep. = epipodite. pr. = protopodite.

ex. = exopodite. v. 1. = ventral integument.

NEOLENUS SERRATUS (Rominger)

VOL. 67, NO. 4, PL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

NEOLENUS SERRATUS (Rominger)

NO.

APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 19

MMI MALS! SCSFREUS (ICOUMIAP EN )ia a isin's dc ares naj vied a aolceciecu cvneeoecessees

FIGS tT.

(X2.) The specimen illustrated by this reproduction of an

untouched photograph shows a pygidium to which the
ventral surface and appendages adhered when the thorax
and cephalon were broken up and pushed to the right side,
dragging the legs out in a fan-shaped manner. A further
description is given under fig. 3. U.S. National Museum,
Catalogue No. 65514.

(X 2.) Photograph of the matrix of the left side of figs. 1 and

3, reversed so as to show the appendages adhering to it in
a natural position. These have been drawn in on fig. 3 in
order to restore some of the finer parts that were lost by
exfoliation when the shale was split open at the quarry.

(xX 2.) This distorted and crushed specimen has 17 legs (en-

dopodites), several exopodites, and the ends of two of the
large epipodites projecting from beneath the exopodites.
The most important evidence given by it is that the ex-
opodite and large epipodite are the same for the abdominal
limbs as for those of the thorax. The epipodites occur
between the leg (endopodite) and the exopodite. The
characters seen on the specimen illustrated by fig. 1 and by
the matrix, fig. 2, are combined in fig. 3.

186 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF -PLATE 2o |

Neolenus serratus, (Rominger) (See plets)i-..- see eee eee eee
Fic. 1. (Natural size.) <A partially exfoliated dorsal shield with finely
preserved thoracic and abdominal legs (endopodites) ;
three of these have the proximal joint (protopodite) one of
which has spines on its proximal end, and another has fine
spines along its posterior margin as well as on its proximal

end. U.S. National Museum, Catalogue No. 58580.
This figure has been published but at the time the
proximal joints of the endopodites had not been uncovered.
(See Smithsonian Misc. Coll. Vol. 57, 1912, pl. 45, fig. 2.)
It was used again in 1913 (Text-book Pal., Eastman ed. of

Zittel, Vol. 1, fig. 1377, p. 716).

2. (X2.) An exopodite of one of the cephalic appendages with
its long slender sete. The thin, plate-like lobe was pushed
up into the eye and molded by it. U.S. National Museum,
Catalogue No. 65520.

3. (X2.) Jointed epipodites flattened on the surface of the shale.
The legs (endopodites) are beneath the epipodites. ‘ Thin,
flat lobes occur beside the axial lobe toward the upper end
of the figure, that were probably attached to the inner side
of the protopodite of the cephalic legs as an endite or
epipodite. They have fine, short spines along the outer
margin that are somewhat stronger than those of the
epipodites of the thoracic appendages. It is barely possible
that these plates were attached to the ventral integument
just under the protopodite joint of the leg. U.S. National
Museum, Catalogue No. 65515.

4. (X2.) Matrix of the specimen represented by fig. 3.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Branchize—NEOLENUS SERRATUS (Rominger)

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 27

PTYCHOPARIA ano NEOLENUS

NO. 4 ; APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 21

Seta HET MIMINE WW AICO. oo co.cc cnc cds eas sanaccece vacdeeccecacdes
Fic. 1. (X2.) A laterally compressed and partially exfoliated dorsal
shield with two flattened antennules projecting from be-
neath the cephalon in front of the glabella. U. S. National

Museum Catalogue No. 65516.

2. (X2.) A broken dorsal shield preserving surface granulation
and form except as changed by flattening in the shale. This
is the type specimen of the species. U.S. National Museum,
Catalogue No. 65517.

Mavenopersa cordilcre (ROMINGES) . 00.0505 cc dec ees ccs cessccvecesecece
Fic. 3. Outline of one of the exopodites shown on the right side of
fig. 5. The broad proximal end and crenulate margins are
two prominent features. The general outline suggests the

exopodite of Neolenus, fig. 6.

4- (X 3.) A nearly entire dorsal shield with 18 thoracic segments.
U. S. National Museum, Catalogue No. 65518. The speci-
men represented by fig. 4 is from locality 14s, Middle
Cambrian: Stephen formation; Ogygopsis shale on Mount
Stephen, British Columbia, Canada.

5. (X6.) A small specimen with the dorsal shield exfoliated so as
to expose the ventral integument of the axial lobe with the
thickened ridges crossing the mesosternites; also obscure
endopodites of the thoracic limbs and clearly defined crenu-
lated exopodites. U.S. National Museum, Catalogue No.
57658. This specimen was poorly illustrated by Walcott,
1912, Smithsonian Misc. Coll., Vol. 57, pl. 24, fig. 2.

penis APP TOIUs” CROMNNGED) oo. vee kk Sheds ecdass cca cdiaweleccias
Fic. 6. (X 3.) Exopodites fringed with flattened sete, exposed by the
removal of the dorsal test. The position of the endopodite
or leg beneath the exopodite is shown on the right lower
part of the figure. U. S. National Museum, Catalogue
No. 65510.

A drawing of a portion of this specimen was published
in 1913 (Text-book Pal., Eastman ed. of Zittel, Vol. 1,

fig. 1343, p. 701).

The specimens illustrated by figs. 1, 2, 5, and 6 are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen for-
mation; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia, Canada.

144

126

188 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL: 67:
¥
DESCRIPTION ‘OB; PLA TE,22
: | aia cs He REE OAR RMS a
Neolenus serratus (Rominger) 5d plaid cEeatialtae clans Bee E LE ee .. 126

FIG,, Is ues) In the specimen represented a this figure ‘the large,
flattened exopodites (ex) have been bent forward and also
pushed more.or Jess to the right of their original position.
The distal end of three of the epipodites (ep) projects
slightly from beneath the thin: fringed exopodites on the

. right side. .The caudal rami-and some of the posterior legs
(endopodites) project backward from beneath the pygid-
ium. Fig: 3, pl. 20, shows the epipodites more distinctly,
also that their position is above that of the endopodite.
U..S. National Museum, Catalogue No. 65520.

The exopodites of Ptychoparia (pl. 21, fig. 5) are similar
in general form to those of Neolenus, and the same is true
of the exopodites of Kootenia dawsoni (pl. 14, fig. 3).

The specimens illustrating Neolenus serratus are from locality
35k, Middle Cambrian: Burgess shale See of the Stephen for-
apts, Peak, I mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia, Canada. ap

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 22

NEOLENUS SERRATUS (Rominger)
Illustrating exopodites

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 28

NEOLENUS SERRATUS (Rominger)

NO. 4 APPENDAGES OF TRILOBITES 189
DESCRIPTION OF PLATE 23

PAGE

MIGO LENA SESE EM BIESIn CIN OMMMO ET) cists ote Aoi alacie oes weisie coe stim cle cd <oulsiaee weeds wa 126

Fic. 1. (X2.) Partially exfoliated interior of a specimen where the

2. (X2

appendages on the right side have to a considerable extent
clung to the specimen. These show the leg (endopodite),
the end of the larger epipodite, also the outer portions of
the large setiferous exopodite. U. S. National Museum,
Catalogue No. 65521.

.) Untouched photograph of the right side of the speci-
men represented by fig. 1. Inserted here in order to show
to what extent fig. 1 has been retouched. It is impossible
in photographing specimens of this character to so reflect
the light that it records all the details.

IgO0 SMITHSONIAN MISCELLANEOUS, COLLECTIONS VOL.

DESCRIPTION OF PLATE 24

[sotelus walcotty Ulrich s: occ c0.c4i cs occ cs selec oa sat os cileeee
Fic. 1. (X 3.5.) A very perfect dorsal shield retaining traces of the
fused segments of the cephalon and pygidium and the points
of attachment of the muscles of the median lobe of the
cephalon and thorax. This illustration should be carefully
studied in connection with pl. 25. U.S. National Museum,
Catalogue No. 61261.

The specimen illustrated is from the Ordovician: Trenton
limestone; 1 mile (1.6 km.) east of the Trenton Falls, in

town of Russia, Herkimer County, New York.

[sotelus gigas var. insignis Ulrich? 2.3 b...1 2 en ke ee
Fic. 2. (Natural size.) Natural cast of the interior surface of the test
of a pygidium on which 14 fused segments are clearly
outlined. U. S. National Museum, Catalogue No. 61255.
The specimen illustrated is from the Ordovician: Trenton

limestone; Covington, Kentucky.

Tsotelus maximus Wocke (See pl. 25, tie. De: ois ewe ate ete eit eee

Fic. 3. (About one-half natural size.) Matrix of the specimen repre-_

sented by fig. 3a, showing the impression made by the
thoracic legs, and traces of the legs to the extremity of the
pygidium. U.S. National Museum, Catalogue No. 33458.

3a. (About one-half natural size.) Ventral surface of a specimen
preserving more or less of the thoracic legs. The matrix of
this specimen is shown by fig. 3.

These two figures are from untouched photographs, and are in-
serted for the purpose of showing the data upon which the appen-
dages shown by fig. 1, pl. 25, are based.

The specimen illustrated by figs. 3, 3a, is from the Ordovician:
Cincinnatian (Richmond) ; Oxford, Ohio. U.S. National Museum,
Catalogue No. 33458.

134

133

SNA LOS!

i alee a $% “Id ‘b “ON ‘29 *10A SNOIL9031109 SNOANVIISOSIN NVINOSHLIWS

VOL. 67, NO. 4, PL. 25

SMITHSONIAN MISCELLANEOUS COLLECTIONS

ISOTELUS MAXIMUS Locke

NO.

APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 25

Tsotelus maximus Locke (See pl. 24, figs. 3, 3@).........ececeeceeceeeees

IG. on.

(Natural size.) Illustration of the under side of the original

specimen with the shaded outlines of an entire interior of a
dorsal shield projecting beyond the broken specimen on all
sides. The 26 pairs of appendages preserved include the
legs (endopodites) and traces of the sete of an exopodite

’ on the right side. The joints of the legs represent all that

is shown in the matrix and relief. The most prominent
character is the very large proximal joints (protopodites)
of the legs, which correspond to the large protopodites of

IgI

Neolenus (pl. 18) and Triarthrus (pl. 32). U.S. National

Museum, Catalogue No. 33458.
The specimen illustrated is from the Ordovician: Cin-
cinnatian (Richmond) ; Oxford, Ohio.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 26

SECTIONS OF TRILOBITES
CALYMENE ano CERAURUS

Fic. I.

(X 3. Untouched photograph.) Transverse section through
the head from the anterior side back to the lower posterior
margins and thence across five segments of the thorax of an
enrolled specimen. The large basal joints (protopodite)
on five pairs of legs are shown. The four lower pairs
on the right hand side of the figure are cut nearly on the
longitudinal axis of the joint, while those on the left are cut
across diagonally, which makes their sections much shorter.
The two joints at the top which correspond to the fourth
or fifth thoracic segment give the characteristic section
where the joint is cut across obliquely (See also pl. 26,
fie. 14:3’ pl. 27,°figs: 1,2, 4).

Several joints of the leg are attached to the upper right
hand basal joint, also a short section of the coiled portion
of an exopodite. On the left side a section is shown of the
epipodite with its attached sete. Both the exopodite and
epipodite are so delicate in the slide that the camera failed
to reproduce them. They are restored in fig. 2.

The filling of the cephalic cavity is shown in the lower
portion of the figure, also the outline of the eye on the left
side, and the basal joint of one of the cephalic legs. The
next pair of joints above presumably belonged to the
cephalic region.

A drawing made from the section represented by fig. 1, and pub-
lished by me in 1881 (Bull. Museum Comp. Zool., Harvard
Coll., Vol. 8, pl. 3, fig. 3).

(X 3. Untouched photograph.) This section is essentially the
same as that represented by fig. 1, but varies in details. It
illustrates the tapering out of the proximal end of the basal
joints (protopodites), a character that is also indicated in
figs. I and 4.

(<4. Untouched photograph.) Another section similar to that
represented by figs. 1 and 3, in which the two pairs of large
upper protopodites approach closely and they are also pro-
vided with minute spines on their proximal end.

Traces of the spiral portion of the exopodites are faintly
shown on the left side. These are very clear in the section
but do not photograph well. The same is true of the same
appendage in the enclosed space on the left side of fig. 3.

(<4. Untouched photograph.) Central portion of a section,
showing the basal joints of the leg cut across obliquely,
also the filling of the visceral cavity beneath the thorax.

(<4. Untouched photograph.) Section cutting through the
head in nearly the same direction as that represented by
fig. 1. It shows, however, the hypostoma, the basal joints of
the legs, and some of the following joints. One of the most
interesting features is the presence of the basal joints of
two of the anterior slender cephalic limbs that in the section
are between the large joints and the hypostoma. This sec-
tion also shows traces of the exopodites.

(X 3. Untouched photograph.) Section through the thoracic
portion of an enrolled specimen, showing large protopodites.

NO. 4, APPENDAGES OF TRILOBITES 193
DETAILED DESCRIPTION OF PLATE 26

PAGE

BAPAC He SERA COMER raise st aida ah Aavna eh slyuKiocinwlen «> cde deb cedecae 147

194 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Ceraurus pleurevanthemus Greens. 5... 6. .diseu von Gs ce oe oe ee eee 148
Fic. 8. (xX 4. Untouched photograph.) Section approximately the
same as fig. 1, showing the proximal joints of the legs and
some of the distal joints, also traces of the spiral portion
of the exopodites.
The enlarged basal joint shown on the left side near the
outer edge may have been one of the enlarged joints of the
posterior cephalic leg.

Figs. 1 to 8 are given for the purpose of iilgsteaaee the large
elongate proximal joints (protopodites) and to show that their inner
ends are drawn in toward the median line of the longitudinal axis
of the ventral surface and that from their form and position they
undoubtedly were closely allied both in shape and function to the
proximal joints of the limbs of Neolenus and Triarthrus.

Calymeneé senaria ‘Conrad s;.< cass «co css es Oe ea otis ose eee eee 147
Fic. 9. (3. Untouched photograph.) Transverse section through
the head, which cuts across the proximal joints of some
of the cephalic legs, the hypostoma, and the enlarged
basal joints of the posterior pair of cephalic legs. Other
portions of various legs are cut across, which are out-
lined in the drawing (fig. 10).

10. (X 4.) Drawing based on the section represented by fig. 9.
This was published as fig. 1, pl. 6, in 1881 (Bull. Mus. Comp.
Zool., Harvard College, Vol. 8).

II. (X3. Untouched photograph.) One of the best sections
illustrating the cephalic legs. This shows the large proximal
joints of the posterior pair and the relatively small joints
of the second and third pair of legs.

This section was used as the base for a drawing published
in 1881 (Bull. Museum Comp. Zool., Harvard Coll., Vol. 8,
Die Te tee10)).

12. (5. Untouched photograph.) This section is nearly on the
same line as that of fig. 11. It is given to show the sup-
posedly enlarged distal joints of the posterior pair of the
cephalic legs.

13. (3. Untouched photograph.) Another section showing the
enlarged joint similar to that of figs. 9 and 12.

Ceraurus pleurexanthemus Green, 2.0.0. .500 00 ec cececeedevneceaccecectec 148
Fic. 14. (XX 3. Untouched photograph. ) De yusvense section of the
thorax of a specimen showing on the right side an oblique
section of the proximal joint of the limb, sections of a
crushed and broken leg on the left side, and sections of the
support and the drawn-out, ribbon-like, more or less coiled
exopodites.
This section was illustrated by a drawing in 1881 (pl. 2,
fig. 3, Bull. Museum Comp. Zool., Harvard Coll., Vol. 8).
15. (X3.) Photograph of a thin section cutting across on the
left side a protopodite which has some of the fine spines
attached to its ventral and inner margins.

All of the sections illustrated on this plate were made by me and
are now in the Museum of Comparative Zoology at Harvard Col-
lege, Cambridge, Massachusetts.

The specimens illustrated are from the Ordovician: upper portion
of the Trenton limestone; 1 mile (1.6 km.) east of the middle fall of
Trenton Falls, on the West Canada Creek, in the town of Russia,
Herkimer County, New York.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SECTIONS OF TRILOBITES
CERAURUS, CALYMENE, WIRE SPIRALS

NO. 4 APPENDAGES OF TRILOBITES 195

DETAILED DESCRIPTION OF PLATE 27

meranrus pleurevanthemus Green. 21... coc ee nc wee ce nee hes eeusiees 148
Fic. 1. (X 5. Untouched photograph.) Section of an enrolled speci-
men, showing one-half of a transverse section through the
thorax. The jointed limb is broken across the proximal
joint and slightly pulled to the left. It shows six joints

: in addition to the protopodite and above the latter traces of
the exopodites. This is the best example of a leg obtained
in sectioning several hundred trilobites. A drawing based
on this section was illustrated by me in 1881 (pl. 2, fig. 2,
Bull. Museum Comp. Zool., Harvard College, Vol. 8).

2. (3. Untouched photograph.) Transversé section of an en-
rolled specimen which cuts through several joints of a pair
of thoracic limbs. These corroborate the form of the joints
shown in fig. 1. A drawing based on this section was
illustrated by me in 1881 (pl. 2, fig. 1, Bull. Museum Comp.
Zool., Harvard College, Vol. 8).

3. (X4. Untouched photograph.) Transverse section through
the thoracic portion of an enroiled specimen, showing traces
of the proximal joints, thoracic legs, and particularly the
spiral structure of the exopodites.

6. (x4. Untouched photograph.) Longitudinal section of the
thorax, cutting across displaced branches of the exopodite.
One of these shows the spiral character very clearly.

7. (3. Untouched photograph.) Transverse section of the
thorax of a small specimen in which the section is cut across
a pulled out spiral of the exopodite.

8. (x5. Untouched photograph.) Portion of a section in which
the section of an unusually long, curved, and somewhat
distorted spiral is preserved.

9. (4. Untouched photograph.) A section somewhat similar
to that represented by fig. 6 where the spiral exopodites
were closely coiled to form a relatively stronger structure.
In figs. 6, 8, and 9 it appears as though the ventral appen-
dages had been displaced and pushed against the interior
of the dorsal shield. These sections are instructive in show-
ing the strength of the spirals and also of the vicissitude to
which the appendages were subjected antecedent to their
mineralization.

15. (X4:) Portion of a seciion cutting through the head and show-
ing five segments of a slender appendage that may have
been an antennule.

mummene-vonotid GOntadic ssi. ee ke cee ae ea we te oe net ol bec ehs 147
Fic. 4. (4. Untouched photograph.) Transverse section of the
thorax of an enrolled specimen, in which the proximal
joints of the legs are preserved, also the bifurcating spiral
exopodites. This section is one of the best illustrating the
exopodites of this species. Another section cut through the
same trilobite a short distance from this one shows the
bifid exopodite more clearly. In a drawing made from this
section and published by me in 1881 (pl. 3, fig. 9, Bull.
Museum Comp. Zool., Harvard College, Vol. 8) the narrow
arm extending down from the protopodite on the right hand
side was considered to represent the epipodite as it was
thought that there were traces of setz on the lower portion.
I now doubt the correctness of this interpretation, as it is
more probably a cross-section of a flattened leg (endopo-
dite). At the time of writing I do not have available for

196 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Calymene senaria Conrad—Continued. PAGE

examination either of the sections cut through this trilobite,
therefore cannot give as conclusive an interpretation of the
section as otherwise would be possible.

A drawing based on this section was illustrated by me in
1881 (fig. 9, pl. 3, Bull. Museum Comp. Zool., Harvard Col-
lege, Vol. 8).

Fic. 5. (4. Untouched photograph.) Section of an exopodite, show-
ing its bifid character and the short, arm-like support. A
drawing based on this section was illustrated by me in
1881 (pl. 4, fig. 3, Bull. Museum Comp. Zool., Harvard
College, Vol. 8).

sa. (X4.) Exopodites from Ceraurus showing the attachment
of the spiral to the supporting basal joint or arm. The
sections used in these drawings are in the Museum of Com-
parative Zoology, Harvard College. The drawings were
first used in 1881, on pl. 4, fig. 4 (Bull. Museum Comp. Zool.,
Harvard College, Vol. 8).

11. (5. Untouched photograph.) Transverse section cutting
across the upper posterior margin of the head and the
anterior upper side of the thorax in such a manner as to
show the filled-in visceral cavity and the basal portion
of several setiferous, presumably thoracic appendages,
tae are interpreted as epipodites (See fig. 2, pl. 26; fig. 12,
pl. 27).

A drawing based on this section was published by me in
1881 in which the right side was restored (fig. 1, pl. 3, Bull.
Museum Comp. Zool., Harvard Coll., Vol. 8).

12. (x4. Untouched photograph.) A drawing based upon a sec-
tion which is now not available for making a photograph.
This shows an epipodite on each side, also the proximal
joint of some of the cephalic legs. The presence of a
metastoma is suggested by the small triangular section
which occurs between the proximal ends of the two large
protopodites.

This figure was reproduced in 1881 (pl. 3, fig. 2, Bull.
Museum Comp. Zool., Harvard Coll., Vol. 8).

13. (5. Untouched photograph.) Oblique transverse section of
several epipodites, displaced and more or less crowded
together. A drawing (fig. 14) based on this section was
published in 1881 (fig. 8, pl. 3, Bull. Museum Comp. Zool.,
Harvard College, Vol. 8).

14. A drawing based on the section represented by fig. 13.

The specimens illustrated by figs. 1-14 are now in the Museum
of Comparative Zoology at Harvard College, Cambridge, Massa-
chusetts.

They are from the upper portion of the Trenton limestone, Ordo-
vician; 1 mile (1.6 km.) east of the middle fall of Trenton Falls, on
the West Canada Creek, in the town of Russia, Herkimer County,
New York.

AG Ng SORE, Oe a OE ee ee Oe ce A Sto
Fic. to. Untouched photograph of wire spirals which have been set in
plaster and filed across so as to obtain sections correspond-
ing to those found in enrolled specimens of Calymene and
Ceraurus.

roa. Photograph of a white wire spiral against a dark background,
illustrating a closely coiled spiral such as those cut across

in the sections represented by figs. 3-6 and 9.

152

VOL. 67, NO. 4, PL. 28

SMITHSONIAN MISCELLANEOUS COLLECTIONS

NINN
lele/aleie

ORDOVICIAN TRILOBITES

NO. 4 APPENDAGES OF TRILOBITES
DESCRIPTION OF PLATE 28

Dcrauyus pleurecaninpeints (GLEEN: «6.5. ee bee ores oye ve cee er sects eee
Fic. 1. (X2.) Untouched photograph of the dorsal shield of a speci-
men from the thin layer of limestone from which all of the
specimens showing appendages of this species and Ceraurus
pleurexanthemus were obtained. U.S. National Museum,

Catalogue No. 18038.

2. Restoration of the interior of the dorsal shield drawn from
specimens associated with that represented by fig. 1. (After
Walcott, Ann. Lyceum Nat. Hist., Albany, N. Y., Vol. XI,
1875, pl. XI. Idem, Bull. Museum Comp. Zool., Harvard
Coll., Vol. VIII, 1881, pl. IV, fig. 5.)

3. Diagrammatic median longitudinal section showing dorsal shield,
hypostoma, and outline of ventral membrane (vm), and
position of intestinal canal, based on data obtained from
thin sections and the specimen represented by fig. 4-

(After Walcott, 1881, pl. IV, fig. 6, Bull. Museum Comp.

Zool., Vol. VIII.)

4. (X2.) Cephalon with the dorsal test broken away over the
cephalic cavity so as to show the inner side of the hypos-
toma and the enlarged opening of the intestinal canal.
Museum Comparative Zoology, Harvard College.

5. (X2.) A transverse section of fig. 4 across the third thoracic
segment. The section of visceral cavity and intestinal canal
are the only traces of parts other than the dorsal shell.
The light spot in the center of each dark spot represents
the light shining through from the front. The division
of the intestinal canal into two parts is undoubtedly of
accidental occurrence.

(Figs. 4 and 5 are after Walcott, 1881, pl. IV, figs. 1 and
2, Bull. Museum Comp. Zool., Vol. VIII.)

(SAREE GEN Ogi) 60190 E61 1 SREY a en ee Oe
Fic. 6. ( 1.5.) Exterior of dorsal shield of the Cincinnati variety of
Calymene senaria, introduced to illustrate the dorsal shield
of Calymene. U. S. National Museum, Catalogue No.

65522.
Locality: Ordovician: Maysville formation; Cincinnati,

Ohio.

MR UID EEC SEMANA OMIT AG. ou arstatuce dix ake We ki oee adc. seeded he cc hice tele av oe
Fic. 7. (X1.5.) Enrolled specimen showing the cast of a portion of
the ventral integument. This appears to show the cast of
the mesosternites, and the openings that led into the base

of the limbs. A median ventral ridge is also indicated.

197

147

198 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Calymene senaria Conrad—Continued. PAGE

Fic. 8. (X 3.) Section cutting longitudinally through the axial lobe of
a partially enrolled specimen. This shows a section of the
dorsal shield for its entire length, the hypostoma and filling
of the cephalic cavity, portion of a distorted cephalic leg
and the ventral integument with its thickened, transverse
mesosternites—of the latter only seven of the twenty pres-
ent are clearly shown in the figure. (After Walcott, fig. 2,
pl. V, Bull. Museum Comp. Zool., Harvard Coll., Vol. VIII,
1881.)

Cyamus scammoni Dall ore koe ios. cosh. OTe oo Meera ee el 173
Fic. 9. (About X 8.) Spiral branchia attached to the third and fourth
thoracic segments. (After Dall.)

Cyamus: dtfusus) Dalliet ins ocr Gictqepits dagen cles den iqeee ee 173
Fic. 10. (About < 8.) Ribbon-like branchiz attached to thoracic seg-
ments. (After Dall.)

The two species of Cyamus are described by Dr. W. H. Dall
(Proc. California Acad. Sci., Vol. IV, 1872, pp. 281-283) and illus-
trated (Marine Animals and the American Whale Fishing, Chas. C.
Scammon, 1874). Of the branchie of Cyamus scammoni (fig. 9)
Dr. Dall wrote, “The third and fourth segments each have a
branchia attached on each side. This, near the base, divides into
two cylindrical filaments spirally coiled from right to left.’ The
branchize of Cyamus diffusus Dall, fig. 10, are described as “ single,
cylindrical, slender, with a very short papilliform appendage before
and behind each branchia.” They are attached to the segments as
shown in fig. I0.

Figs. 9 and Io are reproduced from Walcott, 1881, pl. IV, figs. 9,
10, Bull. Museum Comp. Zool., Harvard Coll., Vol. VIII. The speci-
mens on which figs. 4 and 7 are based are in the Museum of Com-
parative Zoology, Cambridge, Massachusetts.

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SMITHSONIAN MISCEL'ANEOUS COLL=CTICNS

NO. 4 APPENDAGES OF TRILOBITES 199
DESCRIPTION OF PLATE 29

PAGE

RTE tes CECE ie a ca Wh yale ae ibin einia iS Vi6 ini o/xu had eds ove ed ves ee visio em 135

Fic. 1. (6. Untouched photograph.) Two thoracic limbs, showing

the endopodite and the setiferous exopodite. (Collection,
Peabody Museum, Yale University.)

2and 3. (<8. Fig. 3, untouched photograph. Fig. 2, endopodites
and exopodites outlined.) The sete of the upper exopodite
are jointed as indicated in fig. 2. U. S. National Museum,
Catalogue No. 65523.

2a. (X6.) An exopodite illustrating the crowding of the sete
on the jointed arm. This occurs on the same specimen as
the parts represented by fig. 8.

4. (X12.) . Untouched photograph of endopodites and exopo-
dites that were forced from beneath the pygidium. The
endopodites are attached to the protopodites and appear to
have the same structure as those beneath the thorax. The
exopodites, however, show the joints of the supporting arm
‘as overlapping lobes (See fig. 8). A further enlargement is
made in fig. 5 (X 20).

5. (X20.) Enlargement of the posterior portion of fig. 4 to
bring out the minute, overlapping, lobe-like joints of the
arm of the exopodite.

These photographs illustrate the appendages that have
been crowded out posteriorly from beneath the pygidium,
and show the strong proximal joints of the legs and the
setiferous exopodites. U. S. National Museum, Catalogue
No. 65524.

6. (X8. Untouched photograph.) Another specimen showing the
ventral membrane and the bases of the limbs that have
been crowded out from beneath the pygidium. U. S.
National Museum, Catalogue No. 65525.

7. (X8.) Ends of legs (endopodites) from beneath a pygidium.
U. S. National Museum, Catalogue No. 65526.

8. (X18. Untouched photograph.) Minute exopodites crowded
from beneath the pygidium. See text for discussion of
these interesting appendages. U. S. National Museum,
Catalogue No. 65527.

9. (X6. Untouched photograph.) [Illustration of a very fine

pair of antennules, projecting from beneath the anterior
margin of the head. (Specimen in the Collection of Pea-
body Museum, Yale University.)

to. (X 6.) Outer portion of thoracic limb of anterior portion of
right side of thorax, showing the jointed endopodite and
setiferous exopodite. The lower endopodite has a trifid
spinous termination. The joints of the endopodite and the
separation of the base of the sete on the exopodite have
been outlined on the photograph. U.S. National Museum,
Catalogue No. 65528.

200 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Triarthrus becki Green—Continued.

Fic. 11. (X15.) This figure illustrates the structure of the exopodite
of the thoracic limb more clearly than any other specimen
I have seen. The supporting jointed portion terminates in
a flattened elongate narrow lobe or section similar to that
shown in fig. 8, where several of the terminal sections of
exopodites projected from beneath the pygidium. U. S.

National Museum, Catalogue No. 65520.
The specimens illustrated by figs. 1-11 are from locality 373,
Ordovician: Utica shale; 3 miles (4.8 km.) north of Rome, Oneida

County, New York.

—

SMITHSONIAN MISCELLANEGUS COLLECTIONS VOL. 67, NO. 4, PL. 30

1 ja 2 3 4 5 6
Y)
‘oe 8 698 Q ie
44

TRIARTHRUS BECK! Green

NO. 4 APPENDAGES OF TRILOBITES 201
DESCRIPTION OF PLATE 30

PAGE

GAMMERIRGTOCLIGL (GREET Jie teak Uo oie Ok Old MOE cece a's 135

Fic. 1. Natural size and enlargement of an individual having one

thoracic segment.

1a. A narrow and more elongate individual having one segment in
the thorax.

15. Natural size, and enlargement of Ia, to fifteen diameters to
show the character of the head and pygidium and their
relative proportions and size.

1-13. A series of individuals illustrating the gradual development
of the head and thorax on the addition of each thoracic
segment. The pygidium diminishing in size as compared
with the other parts of the body. The numbers 1-13 also
indicate the number of segments in the thorax of each indi-
vidual to which they refer. All enlarged to three diameters.

13. Enlargement to three diameters of an individual having four-
teen thoracic segments.

14. Fully developed individual of sixteen thoracic segments, natural
size. All the larger specimens have been flattened by com-
pression. The convexity in the figure is the same as in an
individual of sixteen segments, 33 mm. in length.

The free cheeks are also pressed out so as to show their
margins.

All of the specimens illustrated by figs. 1-14, 15, are from a locality
northwest of Holland Patent, Oneida County, New York. They
occur in the Utica shale of the Ordovician and are now in the col-
lection of the Museum of Comparative Zoology, Harvard College.

Figs. 1-14, 15, are after Walcott, 1879, Trans. Albany Inst., Vol. X,
Dleenese t=15,

16. ( X20.) Outline of an embryonic specimen that preceded
fig. 1 in development. This shows the cephalon and
pygidium well outlined, and the thorax undeveloped. U. S.
National Museum, Catalogue No. 65530.

The two specimens that were used in sketching this figure
are from locality 373, Ordovician: Utica shale; 3 miles
(4.8 km.) north of Rome, Oneida County, New York.

17. (X4.) Diagrammatic sketch of a specimen preserving the
hypostoma, epistoma, and cephalic appendages. After
Beecher, American Geologist, Vol. XV, 1895, pl. 5, fig. 10.

The specimen is in the collection of the Peabody Museum,
Yale University, from the same locality as that represented
by fig. 16.

18. Diagrammatic restoration of the cephalic appendages: hy=
hypostoma; m==metastoma; I—antenne; 2—first pair
biramous appendages, or posterior antenne ; 3 = mandibles;
4, 5==maxille. (After Beecher.)

202 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67
‘ :

Triarthrus becki Green—Continued.

Fic. 19. (X 15.) Photograph of a specimen that appears to indicate the
presence of epipodites. The flat, rounded, diamond-shaped
lobes originate along the line between the mesosternites and
pleurosternites of the ventral integument, and extend ob-
liquely backward in the direction in which the limbs are
usually found. The dorsal shield was removed from over
them, and in one example nearer the cephalon, the limb is
clearly situated beneath the lobe. U.S. National Museum,
Catalogue No. 65525.

The specimen is from the same locality as the specimen
represented by fig. 16.

20. (about 6.) Limbs occurring on the under side of an indi-
vidual of 14 thoracic segments. Limbs with flattened,
enlarged proximal joints and slender distal joints.

c. Limb preserving large joint of protopodite, four en-
larged proximal joints and three slender distal joints. At
x the point of attachment of an exopodite is shown, and in
the specimen it looks as though f had been broken away
from x.

The above appendages lie so irregularly on the inner side
of the segments of the thorax and pygidium that it is not
practicable to make a satisfactory photograph. U. S.
National Museum, Catalogue No. 65531.

An outline drawing based on this specimen was published
by me in 1894 (Proceed. Biol. Soc. Washington, Vol. IX,
pl. 1, fig: 3)~

The specimens illustrated by figs. 16-20 are from locality 373,

Ordovician: Utica shale; 3 miles (4.8 km.) north of Rome, Oneida

County, New York.

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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 31

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Restoration of ventral surface of
NEOLENUS SERRATUS (Rominger)

Fic. 1. (About two times the average size of the species.) This res-

toration is based on study of all available specimens of the
species that show any of the ventral appendages. Reference
will be made to the specimens illustrated on plates 14-23 in
describing the restoration as they show more or less of
every appendage represented.

(1) Antennules (a). Shown by figs. 1, pl. 14, 1, pl. 15, 3,
pl. 16.

@)PGephaliculimbsis hicsan, 25.3, plo: 2) pla2o; 6; pl. 21, 1,
pl. 22. The endopodites are best shown by figs. I, 2, pl. 16,
and the exopodites by fig. 1, pl. 16, and fig. 1, pl. 22. Whether
the exites, figs. 3 and 4, pl. 20, are present beneath the
cephalon, is not determined. No traces of epipodites were
observed.

(3)) Thoracic limbs; Figs.,1, pl..14, 1, pl. 15) 1 and 3, pl. 17, 1,
pl. 18 (the best one), I, 2, 3, pl. 19, 1, 2, 4, pl. 26 6, pl. 21, 1,
pl. 22, 1, pl. 23. The endopodite is best shown by fig. 3,
pl. 17, and fig. 1, pl. 18. The exopodite by figs. 3, pl. 19, 6,
pl. 21, 1, pl. 22, 1, pl. 23. The large epipodite by figs. 3 and 4,
pl. 20, and the small epipodite by fig. 1, pl. 18.

(4) The abdominal limbs or those beneath the pygidium are not
differentiated from those of the thoracic region. They are
well shown by figs. 1, pl. 15, 3, pl. 17, 1, pl. 18, 1, pl. 20.

(5) Caudal rami (c. r.). These are best shown by figs. 1, pl. 15,
ly eee, Dk. whee

(6) Anal aperture or genital openings (an.): indicated only
on fig. 3, pl. 17.

Observations.—In the restoration all the endopodites are essen-
tially the’same, decreasing only in length and size from the cephalon
to the end of the body. The exopodites, epipodites, and exites are
represented on cnly a few of the limbs as otherwise they would be so
crowded together that it would be difficult to distinguish the various
members of the limbs.

In looking at the restoration the observer must recall that the

‘limbs are seen from their narrow lower side and that they are

quite deep in the vertical section as shown in the transverse view,
fig. 2, pl. 18. The latter view also shows the protopodites, endopo-
dites, exopodites, epipodites, and exites in position.

This restoration should be compared with the restoration of
Triarthrus on pl. 32 and of Calymene, pl. 33.

NO. 4 APPENDAGES OF TRILOBITES 203
DESCRIPTION OF PLATE 31
Legend :
d.s.= dorsal shield. ep. = epipodite.
hy. = hypostoma. ex. = exopodite.
a. = antennules. exi. = exite.
an. — anal aperture. pr. = protopodite.
c. r.= caudal rami, v. 1, ventral integument.
en. = endopodite.
PAGE
INC OLEH UW Sues CHL GU Ste IN@ININGEL)) a Adres cia oe aro nines satis ceteul Se oe eles aledssceon 126

204

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION (OF PLATE 32

Legend
d.s.—= dorsal shield. ep. = epipodite.
hy. = hypostoma. ex. = exopodite.
a. = antennules. pr. = protopodite.
en. = endopodite. v. 1.== ventral integument.
PAGE
Triavthvrus’ decks. (Geen: «556s eric iln notice en Or olen kan eee 135

TG) si

(About 3 times the size of the average adult specimen of the

species.) This restoration of the ventral surface and limbs
is based on study of all specimens available at this time
and old notes on some of those in the collection at Peabody
Museum, Yale University, a few of which were illustrated
by Beecher.

The specimens illustrated on plates 29 and 30 were
studied with others when making the restorations of this
species. From the one represented by fig. 10, pl. 30, I first
gained the impression that there was a small epipodite
attached to the proximal joint of the leg. From figs. 2-5,
8-11, pl. 29, the conception of the structure of the exopodite,
especially the transverse, lamellated joints suggesting the
endites of the limb of Apus was obtained. Fig. 4 led me to
consider that the leg (endopodite) beneath the pygidium
was similar to that of the thorax and that the phyllopod-
li@ endites were part of the exopodite and not of the
endopodite as tentatively interpreted by Beecher. Fig. 7,
pl. 29, and fig. 20, pl. 30, illustrate the expanded joints of the
endopodites.

The restoration has quite a different aspect from that
made by Beecher although the essential elements of struc-
ture are the same. The protopodites are placed in what is
considered to be their normal position and the flattened
joints of the endopodite are given as nearly vertical instead
of being on the plane of the ventral surface of the body of
the trilobite. Beecher shows the protopodite, endopodite,
and exopodite in their approximately natural position in his
restored transverse sections of the thorax and appendages.

Observation—In looking at the restoration the observer must
recall that the limbs are seen from their narrow lower (ventral)
side and that they are quite deep in their vertical section as shown
by the transverse views (pl. 34, figs. 4-6) of the thorax.

This restoration should be compared with the restoration of the
ventral side of Neolenus (pl. 31) and Calymene (pl. 33).

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 32

FOREN
7) [Thpsiliede Lig 2idae
Ss — Z

—

Sh
2 oe aia indo 1

—S
Su —

te Tia
se or pn

Ee we =a a \\

ae
yy, a il

——

5 en

—— aie nw LS S SS

= ii

Yl in >

ML LL LTA

SS
: UMN
— SS =
= == NS =~
>

poe?

My
M0

so: Lin TERS brag Ss Ss
i Fil TILLY: Ws [s, Se aa \ A
, ZIT) YD, ger Ss = =
TTT (ge, — ir co
gs aT

D cae ro
>

es Co ve
Ve gus We ee e

See

Restoration of ventral side of
TRIARTHRUS BECK! Green

VOl. 67, NO. 4, PL. 33

SMITHSONIAN MISCELLANEOUS COI LECTIONS

Sy RE Gace
areas ad Sane il
[fae | \E I |

\ ea
Soe Bes

Restoration of ven‘ral side of
CALYMENE SENARIA Conrad

NO. 4 APPENDAGES OF TRILOBITES 205
DESCRIPTION OF PLATE 33
Legend
d.s.= dorsal shield. ep. = epipodite.
hy. = hypostoma. ex. = exopodite.
a. = antennule. pr. = protopodite.
en, = endopodite. v. i.= ventral integument.
PAGE
PEM PNE SS PSE MIET AAO E ESTEE TIA © yo 0 oreo n'ai crcl ec eis & 9. oreo ekataies Seiecetw att-0 «ches ores aw He 147
Fic. 1. (About two and a half times the average size of the species.)

This restoration is based on my studies of the ventral
appendages of Calymene senaria from 1875-1880, and pub-
lished in 1881. The restoration of 1881 is taken as the base
and such changes made in it as the discoveries of anten-
nules and long protopodites necessitate. Only a fragment
of an antennule has been seen, but with fine antennules of
Neolenus and Triarthrus for study I do not hesitate to put
them in the restoration of this species. Through the kind-
ness of Dr. Alexander Agassiz I had the opportunity of
making a photograph of the original thin sections which I
made 1875-1880. Some of these are reproduced on plate 29.

Observations —In looking at the restoration the observer must

recall that the limbs are seen from their narrow lower (ventral) side
and that they are quite deep in the vertical section as shown in the
view of the transverse section of the thorax, fig. 2, pl. 34. The
latter view gives a side view of the entire limb.

This restoration should be compared with the restoration of the
ventral side of Neolenus (pl. 31) and Triarthrus (pl. 32).

206 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 34

Legend
d.s.= dorsal shield. exi. = exite.
en. = endopodite. int. = intestinal canal.
ex. = exopodite. pr. = protopodite.
ep. = epipodite. v. i. ventral integument.
PAGE
Ceraurus pleurexanthemus Green. .s..5...5..5ed a csn0 sang eee eee 148

Fic. 1. (X abouts.) Transverse diagrammatic sketch of one of the
anterior thoracic segments presenting a side view of the
ventral appendages as far as known. Some of the sections
affording data on the limbs of Ceraurus are illustrated on
PISHZ2On2 7.

Calymene*senarna Conrad (See pla3a)i- neces el eee ee nee
Fic. 2. (x abouts.) Transverse diagrammatic sketch of one of the
anterior thoracic segments presenting a side view of the
ventral appendages as far as known. Some of the sections
affording data on the limbs of Calymene are illustrated on

Disezon27.

Neolenus serraius (Rominger) (See pln3t) ss... ec. ae ees ieee
Fic. 3. (Xabout3.) Transverse diagrammatic sketch of an anterior
thoracic segment presenting a side view of the ventral

integument and the limbs.

Triarthrus becki Green (See pl. 32)....... Pe rine eer otiirs pian 65.0.0 .5c
Fics. 4-7. (X about 5.) Transverse diagrammatic sections of thoracic
- segments and appendages. Fig. 4= posterior side of third
segment, showing the strong, jointed arm of the exopodite
and its attachment to the distal end of the protopodite;
5 = anterior side of the third thoracic segment and limbs,
showing the setiferous exopodite, the endopodite, and the
small epipodite; 5a—section of the arm of the exopodite,
showing the manner in which the setz are attached to it;
=anterior side of the eighth thoracic segment with three
enlarged joints on the leg (endopodite) ; 7— posterior view
at the third segment of limbs of pygidium; the endopodite
has five expanded joints and a slender distal joint.

147

126

135

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6/, NO. 4, PL. 34

qn a
jit

aN
Ute

CAMBRIAN ano ORDOVICIAN TRILOBITES
with ventral appendages
Transverse diagrammatic sections

VOL. 67, NO. 4, PL. 35

SMITHSONIAN MISCELLANEOUS COLLECTIONS

OOLGPAA LAF AGAL

DIAGRAMMATIC SKETCHES OF THORACIC LIMBS

TRILOBITES ano REcENT CRUSTACEANS

NO..4)7 APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 35

Legend
en. = endopodite. bs. = basopodite.
ex. = exopodite. . exi, — exite.
ep. = epipodite. gn. = gnathobase.

cx. = coxopodite.

Anaspides tasmanie G. M. Thomson (See text fig. I, p. I7I) ...........

Fic. 1. Enlarged diagrammatic outline of second thoracic limb. (After
Calman.)

2. Enlarged diagrammatic outline of first thoracic limb. (After
Calman. )

Paranaspides lacustris Smith (See text fig. 3, p. 172).. Pe SE Sere ren
Fic. 3. Enlarged diagrammatic outline of first thoracic limb. (After
Smith, Proc. Royal Soc. London, Ser. B, Vol. 80, 1908,

p. 471, fig. 6.)

DRA CIAL SEF FATES CR DOMDLOL in vicec oni vio See ceive area oS. clus eya ao 4 ox wees
Fic. 4. Diagrammatic sketch of a thoracic limb to illustrate the several
parts and their supposed position in relation to the protopo-

dite.

PeHaT LILES SS UEC u TE CII ee ald Site coalesce ahd Boa: nigh oVeheSie'e vo Sie
Fic. 5. Diagrammatic sketch of a thoracic limb showing the protopodite,
exopodite, and supposed epipodite.
q
Calymene senaria ‘Conead saith Nala af Soha aees Te GRC ene Cerne, ae ae
Fic. 6. Diagrammatic sketch of thoracic limb, neat the protopodite,
endopodite, spirals of exopodite, and setiferous epipodite:

Ceraurus pleurcxvanthamus Greet... cn vcges sees ecege ccs ceuseneecane
Fic. 7. Diagrammatic sketch of thoracic limb, showing the protopodite,
endopodite, and spirals of exopodite,

The diagrammatic sketches of the thoracic limbs of the four
genera were prepared for the purpose of comparing them with each
other, and also to form the basis of comparison of the limb of
Neolenus with that of Anaspides, text fig. I, p. 171, and Koonunga,
text fig. 2, p. 171, Paranaspides, text fig. 3, p. 172.

207

126

135

147

148

208 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 36

Crustacean limb, genus and species undetermined.......................
Fic. 1. (X 20.) Drawing based on photographs of several jointed legs
which are preserved on the surface of a small slab of
shaly limestone. They arg, light brown in color and ‘have
a polished surface similar to the chitinous legs of recent

crustaceans.

Ia. (X 20.) Transverse section of a third joint that has been
worked out of the rock.

2, 2a-d. (Xabout8.) Reproduction of photographs of several of
the legs on the slab of limestone. Fig. 2 has eight joints,
fig. 2a six, figs. 2b and 2c eight; fig. 2d is a fragment pre-
serving four joints. The distal joint has been outlined in
fig. 2c. U.S. National Museum, Catalogue No. 65532.

Formation and locality—Ordovician: (Trenton) Cynthiana lime-
stone. Bank of Ohio River below Covington, Kenton County,

Kentucky.

N eolenus-serratus-(Rominger) ....).20..2....220/4e 32.10.00
Fic. 3. (X8.) A small, nearly entire hypostoma enlarged. U. S.
National Museum, Catalogue No. 65533.

Formation and locality—35k, Middle Cambrian: Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field, British Columbia, Canada.

Apus Vucasana.’ Patkard 2... 5c 0 hf UE ee
Fic. 4. (X6.) Ventral view of carapace with hypostoma, cephalic and
12 pairs of the trunk limbs slightly pushed over so as to
show their form and arrangement. The Apus is from a

pond near Aurora, New York.

126

169

—

VOL. 67, NO. 4 PL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

ry?
Ls Piles

we ON

Srek.

a ed

CRUSTACEAN LIMB, NEOLENUS ano APUS

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 4, PL. 37

TRILOBITE TRACKS AND TRAILS

NO.

APPENDAGES OF TRILOBITES

209
DESCRIPTION OF PLATE 37
PAGE
MM MNN CERAM AIE 7G, TEL FURS doe) Silas okt vate nese enc k te de eu cgawbctas 174

[RSet

(Natural size.) Trail on surface of fine compact sand where

the legs were used to push the dorsal shield along while
the edges of it were resting on the sand, thus leaving a
slight marginal groove and a central groove made prob-
ably by the median projection at the end of the pygidium.
U. S. National Museum, Catalogue No. 66136.

(Natural size.) Imprint of short strong legs with an apparent

bifurcation at the outer end. Some of them are tripartite
which indicates a central claw with the two spines. U. S.
National Museum, Catalogue No. 66137.

(Natural size.) Trail where the legs-on the left side left their

imprint for nearly their entire length, and on the right side
only the distal joint and terminal claw touched the sand.
After the trilobite had made the trail a worm came up
through the sand and followed along in the center of the
trail for some distance. U. S. National Museum, Cata-
logue No. 66138.

(Natural size.) <A trail essentially similar to that of fig. 2, but

with the imprint of the leg from the median line out to
its distal extremity. The division of the impression near
the outer end may have been caused by one of the other
legs leaving its impression at a different angle, or it may
have been that the exopodite had a sufficiently strong sup-
porting arm to make an impression. U. S. National
Museum, Catalogue No. 66139.

(Natural size.) Trail cut deeper into the sand than those

represented by figs. 1-4. U.S. National Museum, Catalogue
No. 66140.

The specimens illustrated by figs. 1-4, 4a, are from locality 73,
Middle Cambrian: Tapeats sandstone; Tonto group; Quagunt
Valley, Grand Canyon of the Colorado River, Arizona.

(Natural size.) This track was made by the claw and end of

the distal joint of the legs when the animal was ascending
a slight muddy slope. U. S. National Museum, Catalogue
No. 66142.

The specimen represented by fig. 5 is from tfocality 8u,
Middle Cambrian: Flathead sandstone and shales; 4 miles
(6.4 km.) above Walker’s ranch in canyon, North Fork of
Dearborn River, Lewis and Clark National Forest, Montana.

5. (Natural size.) Cast of a trail made by the protopodites and

legs, the latter showing to the right beyond the cast of the
deep, narrow impressions made by the protopodites. U. S.
National Museum, Catalogue No. 66141.

From locality 3i, Middle Cambrian: Wolsey ? shale;
about 6 miles (9.6 km.) west-northwest of Scapegoat Moun-
tain on the Continental Divide between Bar Creek and the
headwaters of the south fork of the North Fork of Sun
River, Powell County, Montana.

210 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Trilobite tracks and trails—Continued.

Fic. 7. (Natural-size.) Trail over relatively soft surface of sand where
the protopodites have sunk into the sand, crowding it up
along the median line. There are a few traces of the leg
beyond portion of the trail illustrated. U. S. National
Museum, Catalogue No. 66143.

The specimen illustrated is from the Middle Cambrian:
Tapeats sandstone, on Shinimo Creek, below Powell’s
Plateau, Grand Canyon of the Colorado River, Arizona.

8. (Natural size.) Trail made on surface of ripplemarked, very

fine sand, where only the ends of the legs touched the sand.
U. S. National Museum, Catalogue No. 66144.

From locality 73a, Middle Cambrian: Tapeats sandstone;
in Chuar Valley, Grand Canyon of the Colorado River,
Arizona.

212 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 38

PAGE

Trilobiie: tracks and trails: ..42.;mcccs «ck ueake cea en eee ee erat /)

Fics. 1 and 2

(xX 3.) Track where the legs appear to have burrowed
down into the sand so as to leave a relatively deep impres-
sion. U. S. National Museum, Catalogue No. 8616.

The specimen illustrated is from the Tonto shale, above
the Tapeats sandstone; Grand Canyon of the Colorado
River, Arizona.

This specimen was illustrated by Dr. C. A. White in
Paleontology, Geog. and Geol. Expl. and Surv. west tooth
Merid., Pt. 1, Vol. IV, 1878, pl. 1, figs. 6a-b.

3. (Natural size.) Trail in which the impressions made by the

protopodites are preserved, also the edge of the dorsal
shield. There are no traces of the imprints of the legs
beyond the dorsal shield. U. S. National Museum, Cata-
logue No. 66145.

The specimen illustrated is from locality 115, Upper
Cambrian: Lower beds at L’Anse Cove, east side of Great
Belle Isle, Conception Bay, Newfoundland.

4. (Natural size.) Photograph of the cast of the trail represented

by fig. 3

5. (Natural ee) Portion of a trail in which the imprints of the

6. (X

protopodites and -part of the inner joints of the leg are
preserved. U.S. National Museum, Catalogue No. 66146.
2.) Fragment of a trail preserving the cast of the impres-
sion of the end of the protopodite and portions of the legs.
U. S. National Museum, Catalogue No. 66147.

The specimens represented by figs. 5 and 6 are from ‘ite
Middle Cambrian: Tapeats sandstone, on Shinimo Creek,
below Powell's Plateau, Grand Canyon of the Colorado
River, Arizona.

NO 4, PL. 38

67,

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

to a

ieee ee

TRILOBITE TRACKS AND TRAILS

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL 67, NO. 4, PL. 39

ie Leal a Seal

TRILOBITE TRACKS AND TRAILS

NO.

APPENDAGES OF TRILOBITES 213
DESCRIPTION OF PLATE 39
PAGE
WEEE AUT P9040. a oc Sat oitia/enie 2 asiesfes on smelssindaa eee bee eens 174

Fic. 1:

(Natural size.) Natural cast of a trail in which at the right

of the figure the trilobite evidently burrowed deeper into
the sandy mud. It then moved a short distance and again
went deeper into the mud. This is better shown by the
fig. 2, which is of a cast made of the specimen represented
by fig. 1, and which represents the actual trail made by
the animal. U.S. National Museum, Catalogue No. 66148.

(Natural size.) Plaster cast made of the natural cast illustrated

by fig. 1. This shows the original trail of the animal made
on the surface of the muddy sand.

The specimen represented by figs. 1 and 2 is from locality
73a, Middle Cambrian: Tapeats sandstone; in Chuar
Valley, Grand Canyon of the Colorado River, Arizona.

(Natural size.) Trail made on the surface of the sand
and natural cast of it represented by fig. 4, which shows the
form of the endopodites that made the impressions shown
by fig. 3. Fig. 3 is made from a cast made of the natural
cast represented by fig. 4. U.S. National Museum, Cata-
logue No. 66149.

From locality 8u, Middle Cambrian: Flathead sandstone
and shales; 4 miles (6.4 km.) above Walker’s ranch in
canyon, North Fork of Dearborn River, Lewis and Clark
National Forest, Montana.

214 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 40

Trilobite tracks and ‘tratls. J. 00. 0.0. one wae co eee es tee 174
Fics. 1 and 2. (Natural size.) Fig. 1 is from a photograph of a cast
made of the natural cast represented by fig. 2 of a trail in
which the protopodites have left their impressions; also on
the left side there are traces of the legs (endopodites).
Fig. 2 reproduces the ventral side of the appendages mak-
ing the impressions. U. S. Naticnal Museum, Catalogue
No. 66150.
From locality 114b, Lower Ordovician: sandstone 1 mile
(1.6 km.) north of L’Anse Cove, Great Belle Isle, con-
ception Bay, Newfoundland.
3, 4,and 5. (Natural size.) Figs. 3 and 4 represent portions of the
natural cast of a trail which is unlike any of the other
trails illustrated. The natural trail is shown by fig. 5. U.S.
National Museum, Catalogue No. 66151.
From locality 366n, Upper Cambrian: Lower Lingula
flags at Portmadoc, Merionethshire, North Wales.
This track is described as Cruziana semiplicata by Salter.

7 antiphase toe ate

67, NO. 4, PL. 40

vol.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

TRILOBITE TRACKS AND TRAILS

VOL. 67, NO. 4, Phe 41

SMITHSONIAN MISCELLANEOUS COLLECTIONS

TRILOBITE TRACKS AND TRAILS

NO.

APPENDAGES OF TRILOBITES

DESCRIPTION OF PLATE 41

WEFAN AY COMA UUGIE SUCH} UM HELIN S cso Popispaj) share) svsyensvarsts wauretalelerd Veale sis lsrepsieasace cee sled ns
Fics. 1 and 2. (Natural size.) Fig. 1 is a natural cast of a large trail

crossed by a smaller one where the animal was half bur-
rowing along in relatively soft sediment, stopping fre-
quently and leaving a trail such as that shown by fig. 2.

It must be recalled that frequently trails were made in
semiplastic mud and that later on sand was washed into the
trails, thus making casts, in which when the subsequently
formed rock is exposed to weathering the shale formed by
the mud dissolves and disappears, leaving the cast of the
trail as shown in this instance by fig. 1. U. S. National
Museum, Catalogue No. 66152.

From locality 73a, Middle Cambrian: Tapeats sandstone ;
in Chuar Valley, Grand Canyon of the Colorado River,
Arizona.

215

216 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 42
Trilobite tracks and tratlss.. 0c. c us 00s 00sssap+nsetaeye ae 174

Fics. 1 and 2. (Natural size.) Right and left side of a portion of a
broad track (13 to 15 cm.) showing trifid termination of the
individual imprints formed probably by the claw and spines
of the distal extremity of the leg. The central portion of
the track has been cut out in order to bring the imprints of
the two sides within the limits of the plate. U.S. National
Museum, Catalogue No. 58593.

The specimen represented is from locality 220b, Upper
Cambrian: Potsdam sandstone; near Beauharnois, Prov-
ince of Quebec, Canada.

These tracks were illustrated on pl. 47, Vol. 57, Smith-
sonian Miscellaneous Collections, 1912.

3. (Natural size.) Photograph of a natural cast of annelid trails,
trilobite trails, etc., which illustrate the abundance of an-
nelids in and on the muddy surface of the bottom over
which the trilobite was foraging for food. U. S. National
Museum, Catalogue No. 66153.

From locality 8u, Middle Cambrian: Flathead sandstone
and shales; 4 miles (6.4 km.) above Walker’s ranch in
canyon, North Fork of Dearborn River, Lewis and Clark
National Forest, Montana.

67, NO. 4, PL. 42

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

giant mi 38.
ee

TRILOBITE TRACKS AND ANNELID TRAILS

INDEX

The references in heavy-face type refer to the pages upon which the genera
and species are described and figured.

PAGE
PNOCOTMIIA ATI PENOASES- INICOLENUS. «. . <muic cece s ceic-< cc calee eis sie veiticeincncs 131
ALAM OVTLECI TASTES" _- Ge ae BeBe BORE EIGE Oe Oe CSCIC chitin Paton inn snicoraaicre 118
Ncassize Or Alexander, acknowledgments: ...c-c+ss00-0s+o0ssersseccs es 205

RSME IG aR ae ETTFIAL HOU Sito, +, challors: syevace a¥ehal ere hewelchobes eis sie Xs) Vie,'silejacsl cle oizjaleerocersiciels 123

CAS Sizae EEO HOS) PLOMISe INACE tO). ccc lec sce seis) vicis «cs. 2. clellsvessiaie’eiee ore 116
AUBERT Ss (EI Sas Re ODER Eee BOP ECO EHO DO CCE eae Ie rina ROA DIOOOD 175
EMU ML OEHEING teOle NIC OVERLIES s cictcle core ators aia ccieicie eicie wis ed c-srsie eye.eiciee serae OAT aT
Amaspidacess compared “with trilobite limbs. <2. - 0. .c.ce.e eres ccc es esse vis)
Pamipacican with’ INCOIENUS..... va sce vnvk © oeln< ci soessccscessees sees 169
NMOS: oc EP aed A Oe AAA Ain nn BA ice nena i ne 166
EENULOMMLORPN COLEMIES. are where hiss Oe oer ee Rhee ek ole oa aetine odoin 170

RESP UGAPT OMe eos ek lect ctehicioe owe wetter twee eae Specter ae 164
Anaspids, compared with Calymene and Ceraurus........00.cc0eveceeees I51
Pym oes compared with Cergurus {00 o... cle ke. Sede cos ceca tee taccesss 207
IN GOUGITS PRRN SAE ARC SOEE DOS AO aeRO RAO 130, 170, 207

REALS, cesie wieresae tecnicos Cs Oe a cane Oe eee See es 171

fre ndeeleashaaniay Ne warAealcitdaryarp avs sos os sicteicte breil ee cree oleiars 170

LES Manic GaaVien AN NOmSOMs CISCUSSEC. 2. eases ce cc nes ome aiccioes aes 170
InapenreGl, jal Fels mae WE ky A Bony ea OAS 5G o cat Re ROTATE ea aCe 207

(HOSE ame, Tiere ciGiawaS brorcrcSto At caueec See See Ree ae ae 171

compared with Neolenus serratus.............. orelotekarel crore 166

He IESG COM Nota faaleta, Pes Wola, Siete Pidietnn Si Sins siaii ase alee: 166

ANGI CSO OCehO te trtl© DIES ev. tas sheers Se /siaera eye Boxe oo sis Riis joleharwre son hohe 174
Antennules, of Neolenus...........00. ECE CEE ED ORE eee Noe 127
ENP PEUGa ese MOLES MONIES PE CIES a. ato.cicc ais cic's ere wio.sieiciaronci te stares See oeawie oeueie 11¢
Rte TTR mes CAME AMI DEST ZC CRG. vera afete eae arcdseavole: Gye evarsvcsecoe okey orcin’ crevetorehersvelevs ereue 177
AUPUG, BAC UTE Gri eit Se eetdess fold Hor Cot OT OED ee OO EE ee ee 150
COMA Pane Camis oI NICONCHIES He. = ralevevepevaya: cia cua si/ofosns olor fevsrdletolicte ole ae 129

RENO LULL! Metre TT ere ave AL AL Te: ato ate staid 136, I41, 170

SEG UHI ATS SUCESOS eee tie Re Ptr oid 275 scene rks 6 aw are 204

LipevD Fo) op SS. Reprtl Nee A ca Ls Ya 125, 163, 167, 169

HE ALEOMEt Omit O MIke wer. Met nm scuet oie teac ioe oo ers stats. ac.e de FerwreccaR nee boca 170°

PRTEN CME CAL GP GCISCUSSEG yee 2 nics Seis. x faisie oie-s so 4 6g ¢ oove'ercue'a's sys sate’ 208

iE /SuDNASCGIRIG Teltce 1 O.Aae 72a AP ea a yin a a 208
eT OV EO ANE SND RL: Bede Ga Gn Oh 2 eR cer A 162

Poapaiase Buriierster,. tamaily named. .7...5 fos. ee css ode en cwe se cee eae 132
Peapniiccukdaymonud, subfamily described!) ). 0... jvagece..s elec eee ee eee- 132
ASTM IANS: (SESUST See SIS CAG POCO OOC BALA UR OIE Ie Ut a Ae OER a a 175
Reem eC rCIE COMER RE se tense sh 2 ih Ss wcicie'e ws ce caidas vg ait pew oe 123, 124
CEsUEpiO MMO AtTMNONItES cs sce ie asass ie so eeiaees ba swieeteasGa.s 123, 124

HOLES a ena OmatciloObitert iene s Ue asic eis eo cee we cio cela ce ese e 157, 158

INDEX
PAGE
Bathyuriscus, trails. oo. caw Porch Meals am xe eens Be one icin he 175
Beecher, Dr.iC) Gi, ‘eitedti. aie <A ssise ciate sp eee ae ecto een oe 164, 165
cited on ‘larval Triarthras. 0x0 fin oe asics eileen te kk ie 143
Ott TrinuMcleus soc este Sas .4 Pareles BROS ee oe ee » 158
ventral) inte@tment, os. 3 s..ccs cass 4 cis see polenta eee 154
descent OF “teilODIte:,, «ct... ne c.cyn ciate eeroteiG et etelels ene 1s) anche oe ee 169, 170
description of characters of Triarthrus............ 137, 138, 139, 140, 141
Triarinrws GG a. 6260 te eee ee + eer One Oe eee 136, 137
Trinwiclews CONCeEWWICUS ~ = cick. sen ns os ee eee 142
interpretation of exopodite of Triarthrus |..%%:5 «.. «2 sods Gee 167
POSIEON OF = TeHtArbHrus er «voc isle te eerie sp ack sieldie Gieteieese teen 121
Bernard, cited. on Apfus and the trilobites!...2..2...5<. .--.¢ sss 167
Beyrich) Prof. imtestinal canal otettilobite 4. ss eect ieet eee 157
Billings, discussion of Isotelus covingtonensis. ....:+.+.+s0+-00+seeeueen 134
Branchiopoda,. appendages. *.\:. 2... vensies se ele dan nine oe eee oe eee 162
relation to Trilobitas.s% ac 0s. cis aaa oo eyna era ete sees See 168
Branchipus, POSWiON het Woe case a's sans tive ssa d ed oe dat eins oe 129
Brigham, G. Ri, acknowledgments......-.2...;, c2nc a: «n\n 118
Brooks, memoir cited (footnote).......... are/#ia dial alore Ali lbs Ree 169
Burgess shale; Stephen formation, fauna. .......2<..o0- +s 117
Bureessian Wepatic: CHCA)... 6.5.44 ve Cotas bis oo cn ee tie eee le 177
associated “with Neolenus? © 00.0 ws cesivie sss seeds sess ee ee 177
Burling, Dr: Lancaster D., acknowledsments!.......2. 08. .l0ee eee 118
Burmeister; . Ched) 26/5 2's, oies5054 cechabeoeeeis a's dete aie ee 123
OM BGWENIPUS, sf aisas Fee 08 Se oishs cha Palen See hee eee ee 120
Calymene Bronenmiart, genus mMamed!s = as. 2e <al clas) os cecil te see eee 147
APPENGAGES | oo sc hedge ss en Mareu tees nee aslebie wie coe ee 162
compared with Cyamus.2 sav. cc cake oot os 2 cle» sees ee 173
Nieolenns and) 7AGri Weis i.e sickens eee 203-205
Triarthrus ‘(thoracic limbs)\......-.. «....s eee 167
Traarthrus BGR: ccc ceaasiacisw ss seein sae eee 137
enrolment s,s... bosses ae okies eentonues ce URE eee nae 125
exopodite, epipodite, cephalic and thoracic limbs............ 160
material-assembled! sy..c.6.i 5a ecauste sreleis one nye oie stato’ eee ee 118
position, Of; Limibs':2..0. ssnme« sacicee ye Sameer Ono eee 164
PLESEEVALMONS 2 ave Sia's .lmleye «0a talal Oe AR aD
protopodite and endopodite....c..-eee eke hee eee 159
HES PLTATIOM ss oo. (6 40 Ga sein etaie aS, eee scale legekessns te: eRe 164
Sections compared withwitre spirals). 4.0... sie 196
thoracic: Vamibss as 2-2.h seeking epreisters sche ope redereie: okie cena 166
compared) with Neolentus...: «inc «a ones See iene oe 166
ventral appendages, \ scuidilewais ue «clels wea ire! selene eee 165
Veltral) IMPS UMEME (. sje. 0). date pole es eee 155, 156
meekt Voersteé, Giscussed 25... 5:2 sian +2 9's aebnjage aes) eee eee 197
figured, pl; 28, fig652.c5% . ins ole eee eee 197

compared with Calymene “sentria... . sd «inssn clase - 197

a ee ee eee

a Dip rmanta al

INDEX

Calymene—Continued. PAGE
RUA COME LO WEESCVINEN 4a. Jaa soos uP ae eee bene SEU tle acelelets 147
Hote der MIS tO Par RON Soy ct wee shies ant ale woke Oe hes 193=198, 205

compared with Calymene meeki Foerste ................0. 107

ECR GUESS ASR et. oat eR cdo eel dasa ss 148, 149

LES OVEIMSH RR A At acres cate SN Sets Meee hee less 133

IN COUT ITS tds pe ede ch acy ERE ithe Siac, Eis Herb Bsc: 6 Aa ROE 150

Wieolenustand I anthigsis.: eee OSS Good 3s 153, 205

Neolenus, Tmarthrus,, and Usotelussca.t......0ccess I5I

Contrasteds Mrmuclews GONGEMUTIGUS 2 cae atos oe vec eses cee 156

ilosicitg 8 2a ARR Acne etcetera ee TRL Se 149

HEStOGAG Oily atl UESeCHONMS rea earrs aah whois icles oe. ciessre, arees eve /e.6.+ 116

GAGGING 2 ceoseu mead Gand Sos hoe aoeta OGr GeO Bod ane ce meron 119

SU TLEIE EST ORS ied Beene eS SS Ae a a 147

HAO NTT DS Negace cod Gus eh on Strobo OR GR nts BeOS Be o cee 166
Galymentdce Mulne-Hdwands, family named... 0. 00... 00-.. se ceeesece oe. 147
Camidail iearanis Gi, ON GOIO RU cise ob dobicloticn obice 6ar/a. Stun pou Sno poledon 6 care eee 131
Ges GCC ACNUIs Mamet: jac ccc c ec ceine sll a) o's « <)6 6 ole sfeltiers, disso e's 148
PADIS ANG NEI AS erence the wRSRO SIGE ORI SCIO DG 2 BIRO DICE RNC frre 162
Cqmpareniwith Calygmenet On JERI SRS ONE) SH ia 166

(CONGN TUG Oe AA TS RETA eR ao oa SAREE AS ee Pe 173

exapodite-and. thotacic danas d\jaeeeietes'e We eS oaed bd oe 160

ALE LIMA SSEMDLEG werner ei cieruayspeeieteleaclac.c. a's ais weerAeee ara alee 118
PIGESEIRVENEL OLAS ie rerseTINNG eR evs x oraz oierals ayo eel oinla a caimerdaied eocete 122

protapodite- and endepodite.c) 22), Khem Base Seek eee 159

ES PAL OM mets eters (aici soyere Tatenstnte edeest ils aregete iettye Sv ee Rha heen aes 164

scetions compared with wire spirals <.. 6.6. 6660 oc cccce ences 196

UMONEISIO, INR Beds Sood NaS ORCC ced Peet Gea oad Bocas cere 166
VelthalmaPPENUAESm aati src ste crsiaisiseacrcwist ase sceeie eae hea doce 165

MEM Utet ITI TS UMM Loe pate lerueNsuepe eet avo seey lovers rmclaleict slevavare sree 155, 156
sleureranthemus Green, GeSscribed. <. 0. i.0sceeen ccs cera «eesee gens 148
HeULed y PIS. 20, (27, 28. $0.52 vegas cde os eG BRS ee Cee 193=197

Bae LATIAIT SEP: ehanle ne AC ocho se ches s,orsieeleialaiele ara w elle laue's alas xlana's 149

Compare dmvyitlieGAMmene wr see Meera eae ities tec eres 148, 149

NICOLE USE ORTON Ce REE Cn ce he aee és 149, I50, 153

Neolenus, Anaspides, Koonunga, and Paranaspides ... 207

Neolenus, Triarthrus, and Isotelus............... 150 I51

Eien tinatate reed rect Panerai ra tetera tere cata tie caters sia coe lg alesse 125

BOCs Meee ee eet te ee atte eet. kote eh taey bee awiels 119

{HOONEEIES TITS Sols, ergy sicccay OUR AE Ga a RES Se OR ae rt 150, 166
Wheminiccmoalten hamily mamedsnetecsticcaeccecs ccc cceeomse Coes cele 148
rami PcuttsrelarieiitO PEMOMtA, 562%. de. cclaseecccneklcclstasacedeeenaes 168
Bopepodasrelationsetonlrilobitar re eck htc rene cs va cee cic ope oa arbi clos oles as 168
Correction, Emeraldella brocki and Sidneyia inexpectans.........000000. 118
Grustacedn,, Ordovician less described) sg oc. see ase fawicle cc cieclec cscs ceeds 154
Mrustacean limb, gen: and sp. undt., discussed. ./.. 0000... oc ee cee e eens 154
RTC fetes he 10, 2. 20-0 cases ahaa cee cs vole cen ui odes 208

sHaRe Or DLetiVve Chall Si... 5. istle castles cans aruicisovnecGe veeadiaeeaa 174

Crusiana semplicata Salter, trilobite trail figured ...............-...00-- 214

INDEX
PAGE
Cyamus, compared with) trilobite ..2)...)./1% -/2 opts vated ate als inte claiete ae 173
diffusus. Dall, discussed. « /. 20202865 Sek th ee. Abate see ee Eze
figured, pl. 28) fig. TOO se.tw. nakierae ts... alts te dd ee ene 198
compared with Cyamus Scammont J .):pyacen-tet- etait ree 198
scammoni: Dall, dis€assed’.<% cerr.c csroisiee lysine eto cere se eee 173
figured; pl..28, fig. -O) 5. <p snu kus acid UD eRe ee 198
compared with Calymene and Ceraurus...........-.+seseee 173
Cyamus diuFusus .....6.0000e8 Peer bi dele ese eee 198
Dally Cited 055 sca oent nec cne.s OMe els Gate othe wise steele sper SS te 198
Decapods, ventral surtacelot Macrouran’-. ..-- ese = ee cei eee 155
Defenserand offense, trilobitesplack Of oa. aceees seers c cee eee 125
WDolntty, Cited ccc cavase re tere ssraievonsce ote, cose susie fae eanteloneke ONS eT ter Te eae 123
Dotichometopuss, trails «oso. cites ase vane «ee ssinres ole olale aerate eee 175
Dorypyge, compared . with -Kootenta... 2...) . 5-2/2 <0, <n5 isis Bee T31, 152
richthofeni Dames, compared with Jsotelus maximus............+ 132
Edriophthalmatan, Koonunga most primitives... seis eieieieeeeene 172
Emeraldella-bvrocki.«cOrrectiomls s. seins ce a + acl eee nee eee 118
Bndopodites, Neolenus o's sew «ee ehite pals eeeelaeeies he ee ee eee 127, 128
OS CUS. [GAAS «,. occig acchyors Bionsin oldie bis, veges Huereias o HSER Se Oe a eee eee 175
Epipodites, of (NGOlenus onc. «mietce isc snes aioe ae eee 128, 129, 130
Buphausiacea. comparison with trilobites ser eer astm ae eel eetee eee 173
Escites, Of Neolags. 6% 00s: Whine «a ctnun wens els sec ustiek eee 130
Food, of trilobites isc ccmcntend shad foo eee eee eee TO Eee 125
Hicks, Mr. Henry,on Drilobitesof Wales. ™...........06 «a. ssseeeeeeeen 120
“Horse: Shoe2ecrabietrails hx ..o5 Sh ace nenin Cees ee 175
Hypoparia ‘Beecher, ordet namiedir nck soem ond~ ocean 2 at ee 153
Hlenide;: dorsal-shield). .ce.3..0 2) Sree cocoxneas el gee 176
Ienus, atticnlate organ. Joes oes os cee eke uk ee ee eee 157
Isopod, compared with Ordovician crustacean leg.................ceeee 154
Isotelus; appendages: —~/.2 eos oa sn. heheh ek eee eee 132, 162
compared with Calymene and Ceraurus.............200. 150, I51
Ordovician crustacean leg... «ccc sib oe ase ee 154
Trai hrus® fonds a Pe. dea oe eee 139
lima bots eae ete mises PF atid suas se 6teha) SRM SEN ogre Coe 163
compared: with. Trarthrus. occa ah sdos soe eee 163
thoracic limbs: 3 sc's4 oo ew. skate Seen eee 166
material assembled. :. ...Pciisnsaacle Grad Ged aan ee 118
protopodite aiid endopodite... . Ach «nanan ese eee eee 159
specimen from Trenton limestone, Ottawa.............c+0e- D2
Er OmiOhOrr. she eset aes feist SRE ee ee I21, 122
from) irenton balls sis Yeo. 5c eee ea eee 122

a a EEE

ee eee

INDEX

Isotelus—Continued. PAGE
eomineioncnes UlrichsaiSst, described: s..0 iim... ae e nee es 134
compared with Isotelus maximus... 00505000. oe cc ce eT cece ces 135

CNIS SPISS een eel BOUNCE AC Ry ge Fo ae es 134

SULIT VTLS 4c ssAtae ie TN, bercteha cle Mra atime cette Bald ohana eeaidec 134

Pigae Viale eseonio: Wirich, idiscusSedet owe cok See WEA eo oie’ woe 134
PRC wes “Tiana, a ote octet aS aIetLA 6 Sia. Wiehe bulse dave cn ed 190

PAE NUSMEOE ET CESCHIDE ig, <lnce evn ale aye stats OR MU e eek oo Snle oa le oe 33
MSMBCC lh aA! figs. a) sale pl, Ss fe hee lee Oe Pees wilt 190, 191

UME a SISTER aN ene eta A aie A a es 132

compared with Dorypyge richthofeni. ....0....c0cccceceuees 132
USOTASNCOCMNETONONSTS OS), 6 is sumdsl ees «ko eee ee ale 135

Nealemies andy Geers, ska ea eka sou ad eee 133, IQI

Sig PEN WBE RYO eats Cas arctPase sehen ah ahalieteley mapas ares o iovatls Sts Kew wl ID Ata oe le 133

Parune ER EOMUe MTP NEMGEUISSEM: ccc ecicte eromeieiee, Gos a. cal w, kids WvcceuteMols a doa.adis 134

SUECP ECGS V0) yee pa 2) go Rene ce er 190

compared with J. gigas var. insignis Ulrich.............:... 134
Eromedirentonm Falls “(LOOtnGte) ws. cio ene vies ei.» cred s zh dire 133

illustrates pygidium ........ Mog cn Sage Oe eee ro a aaa 134

este emia tee niet at {ON (.\ <;1j0.0 Ald aye{ais leila Samara bee lak 2609 1.6 eleiPabin oa ee ok 155
Moonunga, compared with Anaspides ss... sieve. Seo) oo eee ec cca oe 172
Ceranritie, and) POranaspidese sercrnusspasce ee hes sos ea keno bees 207

Per ate ee BOGE, TEXt fs Au rcaderd aici ache See bach n slew Oh oh vidwla « 171
Reon wi ATem als ASSCIIDIER whisk. nurses dere ers eke vc dua Wave ciaaed 118
Picts Lame NE MIE NRE eh found ecto e de os PURER aioe eae ccm odio 2 122

cl vonse Vere Alia] J) aaa 2 2 ge ae Se rr 160

PARC RUREOVV ANCL) hw CESCEIDEG. ceniavecs wes waRe DOR bce ed ec edes cet 131
Fe a np Ostet OR oe 180

AMPCHIUAG Commoner ca eet tae ce OtTa Cs & nee teehee canes cca ad-aie 132

compared with Dorypyge and others.................... 131, 132

exopodites compared with Neolenus ...............0.00c.0 188

SVT LOVTN GIT ee Ut lle prvi yim 2 Se Ee 2 oe a rr 131

eS UNCC GOD FIGHIATUS « .fetcliale's, «/aid'eielastois Goode oe oda veld oo tak eee. 168
Setaghmnients Orlin Giaertd ctor itst. oho es as x ose tees 159

compared s withs NGOlenas dee dees. Pee eke be ledewca case as 129

triloiite dorsal shields yy avn ose 1k, S yolse sew cieediad oc 167

Meet nclsue rater norte ceayS yer easel erteeclar hal crtranctave eS OTOL ks where 124

TAREE OS RASS eek iy eA ap a en ee lr et a 123

SMA AROMA D ba epevcreelsk tole sicleks lets hcierc cick eeiiexco Maas Shs Eos 178

ripe kel cht 61) 3g tae Xe Re rn ere oS a 175

Meeonnell Or ke G., acknowledaments: 5 (eos. tion voice ec ook one 134
Pi teritansdecapods, ventral: SUGLACE ....344-<:.acicrer<lotereisiercrerere Moleeald ic cca s as 155
Malacostraca, compared with Calymene and Ceraurus..........0.-0000. I51
CURIE ISSA DRG” O15 511 00 | a rn ne ee Ce er a 168

INDEX

PAGE

Marrella, compared with Calymene and Ceraurus.............00-cce00s: 152
Priarthrus DeCRUMS uate. so vee ois dian He oR ee eee 137

comparison. with: trilobite: «<< secs cies eels reticent ener 170

splendens Walcott, compared with Triarthrus.......2..2...e0ee00- 140
compared. with. trilobiteacnn wi: .stestae-ee ee ee te eee 170

Matthew, description of fnarthrus Geckta..0. oles e cen eee 137
Mesler,, R.D., acknowledgments... 5<,.4.6 ss osteeleraiicisels setae eee 118
Mesonacids, -dotsal ‘shield; ...):t. 00 <5¢.0¥ssle sO blee eae te pn ee 176
Fusing Of SESMENES.. 50.0.0 ive isi0 se ie we we orsnieeiote wre erolelv nae ate eae 127
Miysidacea, comparison withitrilobiten- anaciitec + ieee eek eae reer 173
relation Of trilobites .j.00.cc0n . has Pow oe teen en bakes cee eee eee 162
PESPILATION | 8 's.5 sacle deo. , <a nla Bue Aare nto talt SP evONN ee ete ero ee 164
Nathorstia, dorsal shield)... fee sccsye baeue'sse es bate sane oe Oe 176
Nebalia, compared with trilobite: 0... .06 052-02: feces noe nee eee 173
Nebaliacess) compared with Niolenuss:) sss. 2s sees ec ee eee eee 173
TESHIF ATION: <5. Ves Sw tin eee ieee ee ore Coie Feo crete nce rete ee oe eee 164
Neolenus Matthew, genus mamed=\ 5c. ese eee > cect rae tee 126
antenniulés OM <<< soulsan caso sess sbaenne ce a ee 117

associated! with Burgessias: -.ccsne eee eee eee er renne 77

Catidal Sram: +h.2 6 vcs comemsionewcncamek pane eee ee 162, 178

compared with Anaspidaced) ....snice cee dlb che dete ee 169

ANGSPIDCS 6s dis oe + bis eens Oe See Re 170; ‘T7 Ee peoy,

Galsjamene< eee eee eee eee 150, I51, 152, 153, 166

COLYMENE SCHATIG. oo.5c00 cae oa a0 csiad tse see 205

CEP duvuUs ~ emidetonkor oleae een ee L505 TST elses econ,

Ceraurus pleurexanthemus .....25s00-%eceshhe sae IQI

TsOtelas . 6d ds. 00a ont AO eRRG ER abo be ee 163

Usotelus: martinis... cee eee eee 133, 134, IQ

KIO OPENIG. | asic ck oisle naive ean Aoi ee ee I3t,i32

Nevalia: ee wb dine Saisie vase ale SO ee Ce 173

Notostraca =. 224.5. 20) % oseeai Gis & Boe eee 169

Ordovician. crustacean leg. :..+..... 22 uces dee eee 154

POPANGSPIGES ) on 6 aan a's daa ota disd ooops 2 oe ee 172

Pity ChOPOTIA, 211.0 sas sears a ee ates eRe ene Ore ee 159

TOQTINTUS bn vind owas ehasabeep abd: pee eee 163

Triarthrus (thoracic limbs), 4. ...:is «es eeiieee eee 167

divtantiriusebe ck ane eee eee 137, 130, 140

dorsalshield sc5..e0.0 borers curses we cates eons eee eee 176

ENFOIMENT 4 sd hota b's wit w wuslalcede Go's Soe ele Oe eee 125

O@RLES! esccseoyolei's, eserves seue’ sid ings 6 cine eral cis erRRt ENG as eRe 161

exopodite, epipodite, exite, cephalic and thoracic limbs....... 160

exopodites compared with Ptychoparia................ aac pe

Kootenta dawsont W.viitas sts eeeiee oe oe be eee 196

Noel oj | ee | Men eC OAR Gn ean Siig hi o3o a" 125

Ibhcc| MOM Ant ar Aetna cain Soto oaate'cor 162, 163, 164

material. asseinbled |. o:cs:e bswcds2 ces » o-cfelele G8 tre > nt eee 118

INDEX

Neolenus—Continued. PAGE
GLESPIGACO My. SMSLEMIN yaar erates GEARS hcienete Gicws eae aoe wartaneatons 164

BL ete tere ICTIGI AES! |, oy deaya/e orale ele <livatsiorcceqe ote! Mai U OTe a aes 5 177

Eecieeeearee Aen \a ray heel Steet. Bakes RRO BU ey oka Oas oi awe 166

Pa Nes eercied statis teeth farsi ovs, putea si Ste dale Uist Mia cache 175

Mecenies Mea MCUUM OES a nia oii, aid wraeral oie, cic SSO CA OET SI obo oo 165

ERPS IC IN OMIT EL), CESCEIDEC. oo:5 ajc ie sects vic a hu v aes werbielble a veacae 126

TST eet G11) ANG 2 BO Ro en ee 180-189

GeV CNC mt peTI a Coy ste Acc’. oe odie ales is ata « atures oleldis rd cakia = o2-aiataie 127

collected im. British eG oltimbiaisd site s:0 sleidc ao oilers haraia « Daas « II7

compared with Anaspides taSMaNI@® 6.536. 0ccc ewe eee vec ccss 166

Calnmrie and DrrtHrus 2 onio0 plan teivicwicieigwa sa 203, 204

PE VGM OOF sa NGUEE Sia oi). 52.5.3 stares ca-elo.e card sing hasan « « 126

DUOMO WYONG Ades He Bed Gk Ge oda Gee OPA E DIB CRS Oe an an Ear 150

SUC IMNARNTS a ce at "oy Sete ORIN as eas Ure kL a gk a Te Pe ee 126

Pepe Ite ASE Sie ont erect here ne ticiat inlegs Bac cudeiaes evra mie 128

iit ate wATBA ENS gL ory). ei eyes ania ls ats a duster argece « 2 aicieS%s 166

PGs thdCe, COMPALISOR “with MN ECOLEUUS.. » «<a sc. «0: sraise\e,0\s\00,s/elnajare.s 0's oe of « 169
Mavmieriruvas tiOracie LtibS. . 6p 36s acted decehe ss gy ee oe ale be dlideowee's 160, 161
PTO Me Sts: Ul tall), “CESCEIDEU..|; ts Ue eeins ceil ase wlssleldie > ¢iclew we biel 153
compared with Calymene and Ceraurus...........00..0e0000 153

SUI tots et save, casa stra a eke OI ore Oe V's bs SR Sees 153

Pra E I Sel TIME EN tc oe a ae FR opr ah ea eee eae td wee ew sda won ben 176
Mewes burineister, family tamed. s.64 06 ..<<% oes oa ew ce nee eb owe e's 135
Oienotmdes, compared with Kootenia:.« so. veal. totes bes ebeeckeeeenws ight
Menmnerecicesal piticld,(LOOMOtE).. oa0cc.000c besa gevessscas cetera 176
rrcchopariayeccher, ,order. named. weds. Obes. Ses ake a vate 126
Ordovicianechustaccanmiles: describedsay: coe. ss nee ce cc Gece kent one eens 154
tie snpl.c SO ieee 1G: Delmas) Si rtcig oer cogs tte MEY os winlee 208

associated with Calymene meeki..........0.cccccccccccccces 154
Maverocepuande beecher, family named: -~..aciedetews la ochuduleke ssecesc 126
Peraeoma Teta hon +t UiTtlO Dita). ic wari /e sic sya/s cielo a = Giclee oleae ee ia 6 leneaae 168
Hae rae RUM eRe re ota PHS) ar ev acces crate af aee nee hcobe Re taiate x germ vata ane che esas a 123
a ePaRS I AEEE SENT MPI CIT bee ic oe rasa ola Sie, late's onleieh ossic OM o-eineed oad iSe“neee xe 120
Paranaspides, compared with Anaspides. 0.6056... 00s cece cwiamenceaacsee 166
EEPOR TUS LG! IC OOMUMEE j.'s uta ev slns dialed vo kote Ga nicl seve ees 207

INC OOUCTITI Sask sf A | AR Ue geet TSE SNAP ala A el We

LEST roc Settle CISCUSSER ce erie eee coteinere eo cites on ak tee ee Oe 170
ATI G Cpl aS miles w Serr ores rere cate dc sls(e ate ees alate les she 207

LE RE MRE teats etree eaters Sea een is LB eae Secs 25k arate 172

Payuocarigs MTeldniow Of tlilopitectOw. co.cc occa ede ccvsvsg cekcusaee 162
Binvlopodsanelatroneta: IntilobItenc.sics cleressiesie eyes clas ine cree nialecbeve oslo 168
Pee aU Pe WEMODIED a s.o'sc oo revises titele veins este Rieck olnd sebase ad eee int;
etAMO nit MME TOUTES mV VALE Sits stctolarsistaltertcatee a etsic cate seta cvater cle cig bis tie’s% 120
Proptessan tumopites: MEMO (.)). 62. 1c ck crea sla dweeces ton eveccces os 124
Peee BMC CCCI. SEAIMIEM <, 2% atk silos idles viele a clo dae g ees sadwee sd sees 147

PPP RICHIE a TECISS “CISCUSSEC vet kee rele «cc cb eeu Sbweberewaciuce 174

INDEX

PAGE

Pivchoparna, compared wath Nieolenws.-- as) aster 159
@XOPOMITS Ts jeiave.s Bisley ssevore ys Racin si Rlee et edeme eters eo eae 160

exopodites compared with Neolenus ...........0:....:c060 . 188

material. assembled « t,..céawe4 sek Cen Ree canbe ee oe eee 118
PEESELVALION: f. c.c i.e WE ee wis Cleie ts aie erie eladelol te staan eee 122

trails: (tie. s.Aste Ah Lee Ree La Oe ORE eee 175

cordillere’ GRominger)). described a...s4+ caren eso eee ee eee 144
hgured: ply 21, Ass. Ay 05 ie. accreaisoletelelehe ear cceerarelora aera one eee 187

associated with Ptychoparia permulta............-.s00+see0 147

compared with Ptychoparia palliseri and other species....... 144

SYMON YIMy i Fee ithe he BRR AEG Boece ae eo eee 144

pallisert, associated with Ptychoparia permulta...............4 Se ely
compared with Ptychoparia cordillere............++-ssneeee 144

permulta, mew, Species, describeders:scacede sesh er ee eee eee 145
fieured.plvet figs. 12". Vee seca ecco eer nee 187

associated with other species... sea. ss ceo e oe oe eee 147

compared with Ptychoparia cordiller@...........0...cee0e = 144

Simiata, ventral mem Dratles vane ses es ociacls oe as eee oe Ps ees)
Raymond) Dr. seercy ©. memoin Dyscsece. es ee eee eee eee eee 118
cited in reference to Zittel-Eastman Paleontology.......... . 169

clic kr nS et errr aT a COU O ERO OS éoc00c oC 176

Salpa, Brooks’ memoir ony (footnote)... .. 0. scidtica- 4 o78- eee 169
SE DAC OMG Ls MEO Gals ORE MEIC SHAG HOA arc huopid ooo oon c 17%; 172
sschizopods,2 comparison with) trilobites-merce acta ee eee aie 173
Shoemaker, Clarence Ro acknowledgments. 2.05. sees eet ete 118, 173
Crawitigis! ec «2a te eR escalate eee 154, 166

Syncarida, Anaspides from Tasmania, New Zealand. .2 2... 0s... see 27170
Felationwort trilobite saeco eee RS 3-30.05 . 162

Trenton Falls, Oneida County, New York, species with appendages...... 119
Triarthrus Green, genus’ named). 0.5.53 f 2 cae ses a eeltem «eee eee 135
allied: 40 VE tenteleis: 'socinioae S nkinws theta oe a cigs Mae ee eee os Ge

ANt SMILES: FOM cs wdye/eveia aida chose aise si nvolera w'sicce Wie els) 6 te ee eee 117

APPEMAAGE|S coarse sys, e wspelaje. bois Seles ew ole 6 chelellana: «Ase eee 162

Compared with Anaspid es nso. Pei 2 ac oi 0 ayn de smieye Se I7I

ADUS ale Sad ieia tits SOR a taste Fete iny « Saku hale ee 169, 170

Apus, Neolenus and Calymene ...........cecees> 203, 204

Calymene and Ceraurus.....s.eceeeee 150, 151, 152, 153, 167

CGLYMENE SENOHG sox <r. ad ¥ainsng otis ee a oe Dae ee 205

Ceraurus pleurexanthemus . . 0. sca 5.-+ ects ae IQI

TSOCOUES™ 5 wigra sia dew valde ws. 6 wis odo Repete archaea 133

Lsotelus maxtmus coccs. soos heen toe eee 191

IN COLENWS: a crradve Seieoitsies onde eee TE ee «167,

Ordovician crustacean les... .}c. 7-ac cen eee ogee

INDEX

Triarthrus—Continued. PAGE
Ciao laa Sahe Vey do aeytoc iste eS reo Roch Gen ae hater EA AIDE EE REL Air ase IcR a oe 125
exopodite, epipodite, cephalic and thoracic limbs............ 160
IRIEL) ON, et A ee cee 0 gO ge AEE 3 168

PROS ILL OND wavacrcrreverctovcloytetetes sacle nseeyskanharcy hchavevaven ee 163, 164

TOY UCT CUN sree cresee stapes eiece hava te ae eNe te cle ae eluate eeeiols 161

EOGACTER arvensis ee ete et ails ate ewe 166, 167

Materia lmassempled) vresvperetoert oot a levee. retite See as 118

oy RESIS LE ea RV Ts a 2S) EN oe ee eh ee 122, 124
protopodite and endopodite. o ssste «esac es Oe oad oo dee sie 159
relation to Entomostraca or Malacostraca.................5- 168
CUARAGERENAS, VG Sere ar SUI GOS Onn cae Ortiorc RSs CELA nee ee ae 125
MOnUT MM AUpEIUA MEN gl mi lolemraic toe eemeret S Ike ears side eWide ote a alee 165

De ocie GLECimUesClI Ded ..cinte cine cree Cereieieelere & outers Votre aiereitie « o:cie-a alate 135
figured pl. 26, hs. I-1ts pl. 3O;MISS) I-20, 6 acl sole sles steree 199=201
CompanedewithinA Pusicceyeresice cere ete ree ceria oe ee 136
Calymene, Neolenus, Marrella. ...0... 20000 ccc cc ceu oes 187

Marrella. Splendens: =....escae os. ewes « OSA Be eS 140

TrtnUcleus CORGENIFICUS Po eijsic oe Mee ae 5 oe ce es 153

HEC PIMEME ce Aditi ee ae easel S OE She PORTER. o's Sedera 143
ABUGEEs Ply SO! HES ath, Hoaset ALG 2 bea eas 201

GISCHSSCUMD YA DELNALU Ec «ola eee be Sao oe be ehelere a tater 168

RRM or ce tear aotn ag SA EYED hs SE Eerie Walesieiols «hee She oted ets 137
(DOUG TD AA ibe Bic ARE 8! 3 Ac a 164

era Ge TADS Mey hi ert Bante SO neorontats ahis’ 167

FUG Mi Mee sec Ny aut fen an We ol eta a ra By 5 criss aah’ Sora aca eSeS. 121

SVALO MI aeertetohataves (ateiorata alsuereinie) al abahar oakeust otspaye i t-4-Wets voi ala isi ha aie uaiieleFote 135
Trilobita differentiated from Phyllopods and Ostracods.................. 169
Feldwon to Branchiopoda and .Walacostratas...<).0.0%< ets a aecs 168
Ostracodas: Copepoda Cirnipediay oss a8- saeco ce aoe 168
Sinienite. ApMentases SUMIMALNIZER . 5. cocc cos Casale a atee deo ds wwnaesscecees 177
COMP Ge Gait ile NT AGI) GAGCeAl saya chores kectoteie e.c1ekie Morel ee ISG «sss y0.0 0 aie 173
ALDOIS 55 wp ieiG SH OSTO COOS Code COMO ROTO e ECR eT eee 163

MEA HEAUIEES SOLU DISC MALS waite -teicla: a x cietords <ntise soias «este at aid ists eyapesns ale 163
comparison suggested with Mysidacea, Euphausiacea, “ Schizopods” 173
GeEscenGenterKomnm GAnGhiOpOGdre tec sieemcks 2 ociec celia cio cies cle «see s.0 sre Waey,
Cea eaar Bae ethos dacs ae Gn IE EERO eae RIP a 169, 170
domsaill Sorel Gesatnmahad core 6 oop COTO EOC Ce ie ae ae are 176
Compared = withteA pusrands IetUeliySn cena tee csc cieeiceie eee os 107

SYEHERS, ot 1 Gs EF oa RESO MES CO RERCIERS OG OCONEE O OROICLE IC CIOICT SIC Cae ne ee 178
(DoT GCE 07 eM RR a Ale oe ht "178
LEGIOVG, <EiAle Snes oh ERI CERES ad OS NOTE 178
intermediate between Branchiopoda and lower Malacostraca....... 162
HEITOS UI TiAl GATI Ale ret cucicreim rc sielen reketetel slevare ete ereeerencie recive win diereveng aus esl bs, 177
PAIN OTT Gs. cts eiseeis cists cee cicieceicle & cicfaless.ceaveleje asec tere Sale ote: « ois 123, 178
MOtRATeCeewt lia Am AGMIALGS ope ces a: cisisicheiesrstieeelaievelets areitielelsicletslele sis e 169
PRSIS EE HOSEN UAC M lee cns.c oa ora's 2 seit ein cic Pe Re ee ase he dig eee howe 178
PEON AM ERE ESCELI EMME E cy teres cio (a cre aie ere eles erie Saveke, evein/ ota) strc creser= s/t 4 168
ROSUNANONT by oa oa ces tere ere OO On nea CLERICS 6 an ice A ase as 164, 178

INDEX
Trilobite—Continued. PAGE
restoration) On tnOLracic Mim bse. tae cis eet ieee teen 160
ventral appendages! 2s). iil: ciuneicts sytet Spee fei See 165
Spa writings abit R55 eb Sia raid ate ascrenct’e ebalctd oie a ore, O otenal ole] ove Oe eee 178
SUBUCUME ES ho 9.5. 0 cece aie ode fefose te le [ot eitelies ano eho lol ussite tonic etal Me one ee Chane) ce asta 154
appetidagesy “lim + scans) oieisacranece saree mere oleae ane 158
Position Of ‘the, LiMDSkes asic «cc ais ae ated me cera ee eee eee 162
tracks and! trails; discussed ..s.2... a. onc cee eee | oe eee 7A gs
feured, (pl, 975 MSS LS). oie saw des ors fe. cies es Cleve even e eRe one 209
Dlr 38, Mes. TO ac ceki a eislties toto emitter erties 212
pl: 30;figswi=4) aia): cccbkebhnie tet Gok aoe oo eee eee 253
Ploy AOp MES MTHS) acces cece aie cles ec ais upre ete Rote ae ete 214
Pl Al; MEST Bos. diss sailors sa dicts oe Sele e%e le ott teeta eee 215
Dili, ABs AIGS. , TSS). oo, dco a's ea aie) «bier a eel 216
Dsinucleidze Emmrich: family named: ..5-.oe-caeeee oe eee eee 153
dininucleus Mirch: scents matned.ys-. ciate ates csi erent hie eter eee 153
exopodite and) thoracic: limbsy.ce.. ose e eeces aoc OR
concentricus Eaton, discussed: 2. a.tc-us) eee oe neh cee cee eee 153
compared with: Iiyiarihrus UCGRise ie eich ete eee 153
contrasted (with Calymene senarta....1.-+ ocean eet 156
goldfussi, intestinal canal .......... s:eierseidld sxteeieains «2 emeseeae 157
Ulrich, Dr. E. O., acknowledgements Cfootnote)'. 2.32... <..<.2 eee eee 133
Valiant,antenne of Trarthrus found by. «2.02. /..02. 2.3. see ee 137
discovery of antennules. eis. . Sie dooce do oe oe 117
Volborth; Dr. A.cde; cited on Tilenus..t5 3.05 cc. gasooe. tee oe eee 157
Walcott, Mrs. Mary V., acknowledgments.......0.....c.0..50000 See 118
Wire .spirals,udiscussed. sian een eee ae ee eee eet eee 152
Heunedspla275 ISM MTOG see eee oe PN Ses cio bic 195
compared with Calymene and Ceraurus .........0.0eeeeecee 195
Ztttels cues 2 2 eee Mesaacr NAL abdlck sau Sete tays eee ee ee 176
Zittel-Eastman Text-book of Paleontology, cited.............eeccecccece 169

_ — eared
i

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 5

CAMBRKIAN
GEOLOGY AND PALEONTOLOGY

IV
No. 0. —MIDDLE CAMBRIAN ALGAE

(WitH PLATES 43 TO 59)

BY
CHARLES D. WALCOTT

(PUBLICATION 2542)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
DECEMBER 26, 1919

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The Lord (atemore (Press

. BALTIMORE, MD., U. S. A.

CAMBRIAN GEOLOGY AND PALEONTOLOGY

No. 5.—MIDDLE CAMBRIAN ALGAE
By CHARLES D. WALCOTT
(WitTH PLatTeEs 43 TO 50)

CONTENTS Sis

SLE LIS Une 059-00 aR a a 218
LAL DIDNRIE: G20 heen AER AE es SOR COEIICU HERE SSIS Ace ES Caen acinar a 219

PGUEROLESTORVE Obie AI@ACt gadis ce oeec Seer et Ue ke os eee ec dokuas 219

Meee MPN CSEE VALI 22). atc vec sinviarsies eee Fae ss ves ba Sale clea d an of 220
ee ema SSDEEIES sorters sehen anche CoOL ore Cole es Cee he Sel sete ah 221

mmpaisa wit Tecent Algae. 022 socacic.cestiee cece ce Cea ee ededeles 232

CODEC OL ONKOL VED AG eB MOR a Ai ear pk at Dees cipParnioy Sta rn Panacea Pe ena ey)

PE AEAS ONS Feelin He aie < «Haina ee aS Oe e ee eee Pea 282
eter Wo MCE a MTEC WAI e \ eas 5c, catiens wrod’ Sole aude beads eee oe ohn 22
Enon ayceae (OLCed WANPAE): .:0-3 bien ow nas rae Nel ed cw bye ths Hecoldsees 22

MAIPRRO CRO CMOS 5 ob ial behy ahs iavcitieicse diate sooied eae Fae told Bake a Dade Mhates 225
(CELE ORES AIRS OS aA Soe b ein ERAS Ee A assy te nal ete ne ge ae SRR 1
Reet ECR TRNAS POLIO A. MU y vcin octafuk ateials sete wrest oie ole e Stud wleovic's wn 225
Cyanophyceae (Myxophyceae) (Blue-Green Algae)................. 225
Pam CumiLOnmMOrONedet: Macc tne yale te eee sta. Sates Aowewcas Weneds 225
Paiauily) POSEOGAGEAE! ./...% siecsjae samicse eases sel pate stata lens Ch ersicy2 225

Gentis NMorduia, Mews PENIS Ae «ciao tlvise be cee a Reeea'es 225

Morania confluens; mew species./........5....0.200.- 226

Morania costellifera, new specieS..........eseeeees 229

Morania- elongata, New. Species). 2). le. eee s oes iss 229

Morania fragmenta, new species................006- 230

Morania ? frondosa, new species.................5- 237

Morania ? globosa, new species...................5- 231

Morania parasitica, mew species.................440+- 232

Moranita: ? reticulata; new species... .....0... 6.06.0 06. 233

Gentiss Marpoliarsnewacenusess. seeiisoes ose cee ce cee ees 2a8

Marpoliarspissa, nem SHECIES 2a. ca... cao cia e cece pws 234

Marpoliaaequalis; mnewaspecieSvaccte so: ...6e6 esses... 235

Pilorannveeacn (Geen UAISAC), spaces dee viet m eterna scan ahjSas nes fads 235
Gents SVuknesSid. Mew BONUS 5 cies sacl asi ose ee seets once 235
Yurkhessia-simplex, néw <SpeciéS. 6.2. sc. ese ses 235

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 5

217

218 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Rhodophyceae (Red Algae) oi ic xe cs te oe ebs oe oot cere ee 236

Family Rhodomelaceae* 25... 2 n.5 cides ns. eos ee ee 236

Genus? Waputikia, mew, Senus’ 32.2.2 21ers 236

Waputikia ramosa,: new Species... ..-.:.:5 0. eee 236

Genus Dalyia; new gentis: Vs wic5.. +. 2. tee eee 237

Dalyia\racemata, new species. < +... ..... scan eee 238

Dalyia nitens, new Species... 0)... ... s/s aes 239

Genus Wahpia, new. @enus: . 42545 .--2-- 2 a+e eee eee 2390

Wahpia insolens, new species... ........ 2.5.2.0. 240

Wahpia mimica, new species. ........2. 2.0.55 selene 240

Wahpia virgata, new’ speCies........2:.0.5. 7 eee 241

Genus Bosworthia, new genus............... ‘og 241

Bosworthia simulans, new species. ......+...<....00. 241

Bosworthia gyges, new ispecies. «..0..43-)-2.200 en eee 242

Calcareous Aleae's .050c ek suien ches sets) « su os, aue tee ep 242

Genus Sphaerocodiam’ Rothpletz.........2... 30) = eee 242

Sphaerocodium ? praecursor, new species.......... 243

Sphaerocodium ? cambria, new species...........-- 243

DESCRIPTION OF PLATES FACING

PLATE PAGE

43, 44,45. Morania confluens Walcott................-...-.+.-.-244, 245, 246
46. Nostoc commune Vaucher, N. verrucosum (Linn.) Vaucher, N. par-

melioides Kiitzing, and Anabaena variabilis Kutzing.............. 247

47. Morania costellifera Walcott and M. elongata Walcott......... acho 248

48. Morania fragmenta Walcott and M. ? globosa Walcott.............. 249

49. Morania frondosa Walcott and Morania species undetermined........ 250

50:, Morania parasitica Walcott. <0 ox ol < oi. 0 ate i Oy nies -ens ee 251
51. Cladophora gracilis (Griffiths) Ktitzing and Dumontia filiformis

(Buds.). Greville: ... enc .ccee dees e Qhis sms 42s otha ee 252

52. Marpolia spissa Walcott and Morania reticulata Walcott............. 253
53. Nostoc sphaericum Vaucher, N. pruniforme (Linn.) Agardiys and

Dasya. gibbesit: Harvey ic. o- caie ss \si0's «0/0 216.0 s/n ie on oi « epee see er 254

54. Yuknessia simplex Walcott and Waputikia ramosa Walcott.......... 255
55. Marpolia aequalis Walcott, Wahpia mimica Walcott, Dalyia nitens

Walcott,.andiDs racemata Walcottice. -. scenes ent oe ee eee 256

56. Dalyia -racemata: Walcott.) i5.685 cis nates os ee 2 eee ee 257
57. Wahpia insolens Walcott, W. virgata Walcott, and Bosworthia simulans

Walcott: ca sic'esoc eer Raa eects eee ee ore aoe eeae
58. Bosworthia simulans Walcott, B. gyges Walcott, Morania confluens

Walcott, ‘and Morania’‘and Trilobites:. ; ee. 205. 2.52 4.55. oe 259

59. Sphaerocodium ? praecursor Walcott and S. ? cambria Walcott...... 260

INTRODUCTION

The presence of an algal flora in connection with a large inverte-
brate fauna of Middle Cambrian age in the Burgess shale has been
known to me for several years, but I delayed studying it in order
to obtain all the material possible from the Burgess Pass quarry
of British Columbia.

NO. 5 MIDDLE CAMBRIAN ALGAE 219

Through the kindness of Dr. Charles A. Davis of the United ©
States Bureau of Mines in 1913 a number of thin sections were made
of the algal remains in which occur what appear to be chains of
cells of blue-green algae (Cyanophyceae) (see pl. 43), and later
a series of slides were cut through the courtesy of Director George
Otis Smith by Mr. Frank S. Reed of the petrological laboratory
of the United States Geological Survey.

All of the type and study series of specimens are deposited in
the United States National Museum where they may be examined
by students.

Habitat—The study of the shales and the invertebrate remains
of the Middle Cambrian Burgess shale in which the algae are found
leads to the following conclusions in regard to their habitat :

The compact, smooth, exceedingly fine-grained siliceous Burgess shale was
deposited from relatively quiet, muddy water. At intervals this condition
must have been continuous for some time as layers of the shale several inches
in thickness have the crustaceans distributed irregularly through them. Where
the shale is in thin layers with distinct lamination and bedding surfaces the
fossils are more abundant but less perfectly preserved.

The presence of carbonic acid gas has been mentioned as follows:* That
carbonic acid gas was present in the mud and immediately adjoining water is
suggested by the very perfect state of preservation of the numerous and
varied forms of life. These certainly would have been destroyed by worms
and predatory crustaceans that were associated with them if the algal plant
life and animals that dropped to the bottom on the mud or that crawled or
were drifted onto it were not at once killed and preserved with little or no
decomposition or mechanical destruction. This conclusion applies to nearly
all parts of a limited deposit about six feet in thickness, and especially to the
lower two feet of it.

Owing to faulting and alteration of most of the shales by shearing the area
available for collecting is limited to about 120 feet (36.6 m.) of outcrop on a
steep slope of the mountain. This condition limits our information as to the
original extent of this remarkable deposit. It was probably laid down in a
small bay or lagoon in close connection with the shallow Middle Cambrian sea.

It is evident that the algae, sponges, annelids, crustaceans, etc., now found in
the shale lived in quiet, relatively shallow waters swarming with life and
readily accessible to the waters of the open sea. In the preliminary study of
the fauna I have distinguished 94 genera in collections from a block of shale
not over 15 (4.5 m.) by 100 feet (29.7 m.) in area and 7 feet (2.13 m.) in
thickness. Individuals of several species of crustaceans occur in large num-
bers at three horizons, notably Marrella splendens and Hymenocarts perfecta.
Trilobites, with the exception of the genera Agnostus and Pagetia, are not
abundant, although their tests almost make up massive beds of calcareous
shales a few feet below the base of the Burgess shale.

Mode of growth of the Algae—tThe absence of evidence of the
existence of a point of attachment on any of the forms referred to

* Smithsonian Misc. Coll., Vol. 57, 1912, p. 42.

220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

’ Morania (pls. 44, 45) except as the colonies were held together in
a mucous or gelatinous matrix leads to the conclusion that they floated
freely in the water and sank to the bottom along with the crusta-
ceans, annelids, etc., that lived among and fed more or less on them.
Small shells (Lingulella), ostracods (Aluta), and trilobites are found
attached to membranous expansions of the plant mass as though
the shells had been lying on the bottom and the algae settled down
over them, and in other examples the algae were on the bottom
and the shells or trilobites became attached to the upper surface
of the algae (pl. 58, fig. 4). Where the algal remains form a layer
-of appreciable thickness in the shale numerous small annelids.
(Canadia setigera Walcott*) are almost always present, but it is
rarely that the larger annelids and crustaceans are associated with
them; this indicates that the algae covered sufficiently large areas
on or near the surface of the water to afford a favorable habitat for
Canadia setigera and other small invertebrates. The species of
algae forming small colonies floated in the water free from those
forming large masses and they were frequently associated with
them.

When we conclude that many of the forms of algae now found
in the Burgess shale grew as free colonies it must be remembered
that most, if not all, of the algal material was carried into the area
by currents and deposited on the muddy bottom of the pool, lagoon
or bay, and that probably none of it- grew in situ. The floating species
(Morania confluens, etc.) were drifted by prevailing currents or
winds and the sessile species (Donaldella insolens, D. mimica, D.
virgata, Waputikia ramosa, etc.) were readily detached by animals
feeding among them or torn loose by currents or waves and drifted
to their final resting place.

Manner of preservation—The algal remains usually occur as
shiny black films on the surface of the hard dark siliceous shale;
this form of preservation is the same as for the medusae, sponges,
annelids, crustaceans, etc., except that the algae were evidently
more gelatinous and membranous; it appears to have made little
difference whether the fossil was a flat, thin frond, a sphere, or a
thick-bodied crustacean; all alike have been reduced to films of
varying thickness without greatly distorting the original outline and
arrangement of parts. The mucous or gelatinous mass of algae;
the spongin and spicules of sponges; the flesh of annelids; the test
and body of crustaceans, have all been replaced by a shiny black

1 Smithsonian Misc. Coll., Vol. 57, No. 5, 1911, p. 110, pl. 23, figs. 1-3.

NO. 5 MIDDLE CAMBRIAN ALGAE 221

carbonaceous-appearing siliceous film containing pyrite in varying
proportions. It is evident that the original organic and inorganic
matter was removed by solution and replaced by the black film,
the original convexity and relief being lost in the process and by
subsequent compression.

The presence of spherical, barrel-shaped and broadly cylindrical
cell-like bodies singly and in chains (pl. 43) of varying length in
association with the fronds of Morania confluens at once raises the
question as to their organic and inorganic origin. Rauff contends
that such bodies are simple balls, cylinders, etc., of pyrite (FeS,)
and are of inorganic origin.’ He states that such black pyrite balls
and strings of balls occur not only in association with sponges and
other organic remains, but also in limestones where there is no evi-
dence of organisms, all of which I freely admit. In the case of
the strings of balls and barrel-shaped cylinders associated with
Morania confiuens, there are the remains of an alga closely allied
in appearance to the Blue-Greens (Cyanophyceae) which have cells
similar in appearance and arrangement to the fossil forms; that
they are preserved in pyrite is to be expected from the fact that the
animal matter of the sponges and crustaceans is replaced by pyrite
in the Burgess shale but in the form of microscopic cubes with
glistening faces; such cubes occur in association with the spheres,
cylinders, etc., found with Morania. I think we have here an illus-
tration of organic and crystalline (inorganic) phenomena. It is
difficult for me to conceive of strings of pyrite balls being assembled
in curved lines of varying configuration unless there were organic
structures that gave them form and direction.

Genera and species—The following genera and species of algae
have been identified:

CYANOPHYCEAE (MYXOPHYCEAE) (BLUE-GREEN ALGAE)
Order HorMocoNEAE
Family NOSTOCACEAE
Morania confluens, new species
Morania costellifera, new species
Morania elongata, new species
Morania fragmenta, new species
Morania frondosa, new species
Morania ? globosa, new species
Morania parasitica, new species
Morania ? reticulata, new species
Marpolia spissa, new species
Marpolia aequalis, new species

+ Palaeontographica, Vol. 40, pp. 328-330, pl. 17, figs. 2, 3.

222 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

CHLOROPHYCEAE (GREEN ALGAE)
Yuknessia simplex, new species

RHODOPHYCEAE (RED ALGAE)
Waputikia ramosa, new species
Dalyia nitens, new species
Dalyia racemata, new species
Wahpia insolens, new species
Wahpia mimica, new species
Wahpia virgata, new species
Bosworthia radians, new species
Bosworthia gyges, new species

Comparison with recent Algae.—All comparisons of the fossil
Cambrian algae with living algae with exception of the genus
Morania are based on similarity of outward macroscopic characters
and form of growth. Anyone possessing a slight acquaintance with
living algae, knows that this is a very uncertain standard as essen-
tially the same outward form may occur in different genera and even
orders. We have in the fossil species only the pressed and flattened
remains of fragments of the original plant and in one instance
possible evidence of the microscopic structure ; in their pressed con-
dition, however, they may be compared with dried herbarium speci-
mens with a prospect of at least pointing out resemblances that
indicate that some of the algae of lower Middle Cambrian time
closely resemble those of the present day.

Cyanophyceae—The Cambrian genus attaining the greatest
development in species and abundance of specimens is Morama, a
form that is so closely allied to the living Blue-Green algae that
I have ventured on both macroscopic and microscopic characters to
refer it to the Order Hormogoneae and with some uncertainty to
the Family Nostocaceae. Marpolia also may be tentatively placed
with the Blue-Green algae, although it could quite as well be grouped
under the Chlorophyceae.

Comparisons —Nostoc commune Vaucher (pl. 46, figs. 1, I@) has
many points of exterior resemblance, also Nostoc verrucosum (Linn. )
Vaucher (pl. 46, fig. 2), with Morania confluens (pls. 44, 45).
Comparison should also be made with Anabaena variabilis Kutzing
(pl. 46, figs 4, 4a). The surface of Morania confluens (pl. 44,

fig. II) is sometimes wrinkled as it is in Nostoc verrucosum (pl. 46.

fig. 2).

Morania ? costellifera (pl. 47, figs. 1, 2) may be compared with
Nostoc parmeloides Kiitzing (pl. 46, figs. 3, 3a-d) and somewhat
in surface characters to Nostoc verrucosum (pl. 46, fig. 2). In exter-

NO. 5 MIDDLE CAMBRIAN ALGAE 223

nal appearance the small masses of Morania fragmenta (pl. 48, fig. 1)
resemble those of Nostoc sphaericum Vaucher (pl. 53, fig. 1). The
large perforated frond of Morania ? frondosa (pl. 49, fig. 1) and
M. reticulata (pl. 52, fig. 2a) may be compared with that of Anabaena
variabilis Kiitzing (pl. 46, fig. 4). The delicate disks of Morania
globosa (pl. 48, figs. 2, 2a-c) resemble those of the living Nostoc
pruniforme Agardh (pl. 53, fig. 2).

Marpolia spissa (pl. 52, figs. 1, 1a-b) had a form of growth appar-
ently similar to that of Cladophora arcta (Dillw.) Kiitzing and
C. gracilis (Griffiths) Kiitzing (pl. 51, fig. 1), and the transverse
walls of the filaments are much like those of C. fracta (Vahl)
Kiitzing and some species of Chaetomorpha, C. clavata (Agardh)
Kiitzing, C. aerea (Dillw.) Kiitzing. Comparison should also be
made for form of growth with Ectocarpus mitchellae Harvey, E.
elegans Thuret, and Pylaiella littoralis (L.) Kjellman.

Chlorophyceae (Green Algae).—The genus and species included
under the Chlorophyceae is Yuknessia simplex (pl. 54, fig. 1), which
is a very doubtful reference.

Rhodophyceae (Red Algae).—This group is represented by a
number of species that indicate that the algae of Middle Cambrian
time had attained a development that included the highly organized
Rhodophyceae, a conclusion that might be anticipated from the
advanced stage of evolution of the associated sponges, holothurians,
annelids and crustaceans.

The fossil forms may be compared with living species on the
basis of external appearance and form.

Waputikia ramosa (pl. 54, fig. 2) has a somewhat similar mode
of branching as Dasya gibbesi Harvey (pl. 53, fig. 3) and the form of
stem and main branches is not unlike those of Euthora cristata
(Linn.) J. Agardh. Dalyia racemata (pl. 56, figs. 1, 1a-c) has trans-
verse lines on its branches that suggest those of Halurius equisetifolius
(Lightf.) Kiutzing, and its branches suggest Carpomitra cabrerae
(Clem.) Kiutzing, and its terminal branches Griffithsia opuntioides
J. Agardh. Wahpia msolens (pl. 57, figs. 1, Ia) branches in similar
manner to Ahnfeldtia plicata (Huds.) Fries and Cystoclonium pur-
purascens (Huds.) Kutzing. Comparison should also be made with
Ahnfeldtia concinna J. Agardh and Gymnogongrus leptophyllus
J. Agardh. Wahpia mimica (pl. 55, fig. 2) with its round stem and
manner of branching recalls Ahnfeldtia plicata (Huds.) Fries and
Ceramium rubrum (Huds.) Agardh. Wahpia virgata (pl. 57, fig. 2)
suggests Ceramium nitens (Agardh) J. Agardh.

224 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

Bosworthia simulans (pl. 57, fig. 3) probably had a form of growth
not unlike that of Dumontia filiformis (Huds.) Greville (pl. 51,
fig. 2) and possibly Dictyota ciliata J. Agardh and D. fasciola (Roth)
Lamour.

We have also to consider that in this Burgess shale flora there
is only a portion of the marine algal flora of Cambrian time, and
this is represented by fragments of plants that grew in a very
limited area tributary to the small basin into which they were drifted
and deposited ; the marvelous part is that we have anything preserved
as fossils of such delicate and evanescent plants; what the larger
algal flora of the great Cambrian seas of North America, Europe
and Asia may have been we do not know, but from this one rich
spot in the Burgess shale, and the great extent and advanced devel-
opment of the invertebrate Cambrian faunas in many areas it is
probable almost to a certainty there was an algal flora present in
Cambrian time along all shore lines and in all bays, inlets and small
bodies of water very much as at the present time. That fresh-
water algae also flourished is indicated by its presence in the pre-
Cambrian Algonkian rocks of the Cordilleran region of western
America.’

Dr. G. F. Matthew has named and described several species of
supposed algae from the Cambrian formations of Acadia, none of
which appears to me to be sufficiently well defined to satisfactorily
prove that they were of undoubted algal origin. :

I have examined the type specimens of Palaeochorda setacea,
which appear to be the casts of trails of annelids that were moving
over and through the sand and mud; the surface characters described
by Matthew are such as occur on casts of trails in a fine-grained
sandstone matrix.

Phycoidella stichidifera* is represented by a specimen that is in
poor condition and also obscure. I doubt if it is of algal origin.

The types of the remaining species I have not seen and cannot
express an opinion on them; they are microscopic in size, and the
illustrations are more or less diagrammatic.

During the forty years in which I have been collecting and ex-
amining other collections except those from the Burgess shale, I
have seen a few fragments that indicated the existence of algae in

1See Smithsonian Misc. Coll., Vol. 64, No. 2, 1914, Pre-Cambrian Algon-
kian Algal Flora, pp. 77-156, pls. 4-23.

* Trans. Royal Soc. Canada, Vol. 7, Sec. 4, 1890, p. 145, pl. 6.

*Tdem, p. 144, pl. 5, figs. 5a-d.

NO. 5 MIDDLE CAMBRIAN ALGAE 225

the Cambrian strata, but none of the specimens gave satisfactory
evidence of their undoubted algal origin. Many annelid trails, tidal
water markings, trails of crustaceans and drifting medusae had been
referred to as of algal origin but all were susceptible of some other
interpretation.

Acknowledgments.—I wish to express my gratitude to the late
Dr. Charles A. Davis for cutting thin sections and photographing
them. The photographs of specimens were made by Mr. L. W.
Beeson of the U. S. National Museum, and the necessary retouching
of the background by Mrs. Mary Vaux Walcott. Mr. William R.
Maxon, U. S. National Herbarium, has been most helpful in calling
attention to sources of information in the collections of the National
Herbarium and in botanic literature. Dr. Marshall A. Howe, New
York Botanical Garden, kindly read the proof to verify the nomen-
clature of the recent algae.

CALCAREOUS ALGAE

Two species of calcareous algae have been found in thin sections
of the Burgess shale from which most of the algal remains described
in this paper have been obtained. Other genera and species have been
described from various Cambrian formations, but as this is a pre-
liminary study of the forms from the Burgess shale they will not
be considered at this time.

DE SCRILATON OF -SPECIES
CYANOPHYCEAE (MYXOPHYCEAE) (BLUE-GREEN ALGAE)

Order HORMOGONEAE'

“Plants multicellular, filamentous, attached to a substratum or free-floating;
filaments simple or branched, usually consisting of one or more rows of cells
within a sheath; reproduction occurs by means of hormogones or resting
gonidia.” * :

Family NOSTOCACEAE*

“Sheaths forming a more or less distinct mucous, gelatinous or mem-
branaceous tegument, mostly confluent, often not present; trichomes consist-
ing of a single row of uniform cells, with heterocysts, usually twisting and

entangled, not branched, showing no differentiation of base and apex, repro-
duction by means of vegetative division, hormogones and gonidia.’’*

Genus MORANIA, new genus
Plant mass (colony) at first small, irregularly globose or spheroidal
with surface raised in low rounded bosses that give the flattened

1 Tilden, J.: Minnesota Algae, Vol. 1, 1910, Minn., p. 56.
? Idem, p. 160.

220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

mass an irregularly circular outline. As the mass expanded it
assumed various forms, bullose, filiform, globose, and spread out
in perforated or non-perforated membranous sheets ; solid or hollow ;
mucous, gelatinous or leathery ;* made up of tangled trichomes often
torulose (chain-like) ; cells irregularly spherical, barrel-shaped or
broadly cylindrical, larger heterocysts, cells intercalary ; gonidia un-
determined. (The cell description is tentative as it is based on such
material as is illustrated on pl. 43.) 7

Genotype—Morania confluens Walcott.

Stratigraphic range——Middle Cambrian, lower 10 feet (3.05 m.)
of the Burgess shale member of the Stephen formation.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, one mile (1.6 km.) northeast of
Burgess Pass, above Field, British Columbia, Canada.

Observations —The above generic outline follows that of Nostoc
Vaucher, as defined by Josephine Tilden.’ It is based on the study
of a large series of specimens and many thin slides. The question
may arise as to why not place the Middle Cambrian species under
Nostoc as they so closely resemble species of that genus. I would
do so were it probable that a genus of the Nostocaceae had persisted
from early Middle Cambrian time to the present. Representatives
of the family might persist for millions of years, but we hesitate to
conclude that the genus has not changed and therefore prefer to
use a new generic term to include the Cambrian forms.

The species referred to Moramia are:

Morania confluens Walcott
Morania costellifera. Walcott
Morania elongata Walcott
Morania fragmenta Walcott
Morania frondosa Walcott
Morania ? globosa Walcott

Morania parasitica Walcott
Morania ? reticulata Walcott

MORANIA CONFLUENS, new species
Plate 43, figs. 1-6; plate 44, figs. 1-11; plate 45, figs. 1, 1a; plate 58, fig. 3
Plant mass (colony) free as far as known, gelatinous, more or
less firm in early stages and irregularly spheroidal in form but
quickly spreading out in very irregular flat or convex forms or in

1 See second paragraph under ‘‘ Manner of Preservation,” p. 221.
* Minnesota Algae, 1910, p. 161.

N@. 5 MIDDLE CAMBRIAN ALGAE 227

membranous perforated sheets that are torn and broken into large
and small fragments. The lacunae or perforations vary greatly in
size, number, and arrangement. Often a group of small colonies
are held together by the gelatinous-appearing base which forms a
film on the surface of the shale ; color unknown; strands flexuous and
more or less entangled; no sheaths or distinct entire trichomes ob-
served ; cells * spherical, barrel-shaped ; heterocysts irregularly spheri-
cal and larger than the cells. (See pl. 43, figs. 2, 4.) Gonidia
unknown.

Observations —There is no uniform outline or base, or point
of attachment of any portion of the fragments of this perforated
membranous frond-like alga. No two pieces agree in size and out-
line or in the size and form of the openings through the dark glisten-
ing surface of the frond. With a magnification of 20 times, long,
fine, irregular, more or less interlacing, flattened, branching strands
or fibers may be seen which run in the general direction of the
longitudinal axis of the fragment of alga in which they occur. The
interlacing effect may have been produced by the matting down of
several layers of irregular strands upon each other. The general
appearance of the alga on the surface of the shale is shown by figures
1-6, plate 43. From the study of these and several hundred additional!
specimens I conclude the alga was in the form of a mucous, gelatinous
mass that formed a plant colony which assumed an irregular frond-
like shape when pressed flat in the shale ; it was built up of flexuous,
curved, more or less tangled strands embedded in a gelatinous matrix.
We do not know the original form of the plant mass further than it
must have been elongate and presumably frond-shaped with numerous
perforations through it of various size. It was recumbent and was
deposited from the water in great profusion on the firm surface
of the mud.

Microscopic structure.—Through the courtesy of the late Dr.
Charles A. Davis of the United States Bureau of Mines I obtained
a series of thin slides made from the membranous fossil remains of
this species. With great skill he cut sections parallel to the flattened
surface which showed in a remarkable manner chains of cells, some
of which are illustrated on plate 43, figures 1-4.

The cells appear to have been spherical, elongate oval, barrel-shaped
and cylindrical ; the sections include long chains of cells that curve

*See second paragraph under “ Manner of Preservation,” p. 221.
*Tdem.

228 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

and bend (figs. 2-4) very much as in the recent Nostocaceae, or the
cells may be in groups or single (fig. 1). The sections illustrated
were cut parallel to the surface of the alga and to the lamination of
the shale which accounts for the success in getting long chains of
cells. No traces of body sheaths have been observed.

Mode of occurrence-—This species occurs abundantly in several
layers of the siliceous Burgess shale and also less frequently through-
out the band of shale which carries a large crustacean fauna; over
1,500 specimens were collected and many more might have been
brought in.

The plant mass may be represented by (a) a small, delicate, irregu-
larly circular film on the shale (pl. 44, figs. 3, 4) which is the remains
of a flattened spheroidal mass; (b) a grouping of the bodies (a)
pressed together on the shale (figs. 6, 7); (c) the beginning of a
flattened membranous sheet (fig. 10); (d) irregularly strung out
group in a gelatinous base (figs. 8, 9); (e) small membranous
fragments (figs. 5, 11) ; (f) large, irregular, perforated membranous
fragments in one thickness on the shale (pl. 45, figs. 1, Ia) or (g)
lying in layers forming beds several millimeters in thickness. The
largest fragment in the collection is 15 cm. in width and 20 cm. in
length.

Comparison with recent algae.—Of recent forms, Nostoc commune
Vaucher (pl. 46, figs. 1, 1a) has many points of resemblance. These
include the small spherical-shaped colonies that form irregular disks
when flattened ; the highly irregular, torn and perforated sheets ; also
essentially the same form of chains of cells. It may also be compared
with Nostoc verrucosum (Linn.) Vaucher (pl. 46, fig. 2) as the latter
has a similar habit of growth in outward form and the surface of VW.
confluens is sometimes wrinkled as in N. verrucosum, but it does not
have the same characteristic surface.

Comparison should also be made with Anabaena variabilis Kutzing
(pl. 46, figs. 4, 4a) which occurs as floating masses on the surface
of the water and in many other forms but these are not as close to
Morania confluens as Nostoc commune. Torn fragments of the red
alga Kallymema perforata J. Agardh resemble the larger perforated
fragments of M. confluens as do those of Ulva reticulata Forsk.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

NO. 5 MIDDLE CAMBRIAN ALGAE 229

MORANIA COSTELLIFERA, new species
Plate 47, figs. 1, 2

Plant mass (colony) free as far as known; irregularly circular
or elongate oval as they occur flattened on the surface of the shale;
probably discoid or semiglobose when uncompressed ; gelatinous or
leathery, strong and not readily torn or broken; surface with more
or less irregular costae or wrinkles that vary in strength on different
specimens, the costae may be the result of the shrinkage of globose
hollow colonies. No traces of strands have been observed; micro-
scopic characters unknown.

Plant masses referred to this species have a diameter of from 3 mm.
to 20 mm. P

Observations.—This species differs from Morania globosa and the
round form of M. confluens in its more leathery appearance, wrinkled
surface and firm outline. In exterior outlines the flattened colonies
of this species resemble the recent Nostoc parmeloides Vaucher
(pl. 46, fig. 3) and somewhat in surface Nostoc verrucosum (Linn.)
Vaucher.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass, above Field, British Columbia.

MORANIA ELONGATA, new species
Plate 47, figs. 3, 3a

Plant mass (colony) free as far as known with an irregular cir-
cular outline as though spheroidal bodies I to 2 mm. in diameter
had been flattened to a film on the shale while held together in a
gelatinous matrix; some of them appear to have split up so as to
give a ragged and sharp outline to the thin films as they occur singly
and in groups in association with the more circular bodies. The
colonies were held together in long strings of gelatinous matter that
trailed in narrow masses in the water; these elongate masses are
usually 2 to 3 cm. broad and Io cm. or more in length and with
indefinite outlines ; some examples appear as if they had been smeared
over the mud as a thin film, while others show laminations caused
by the crushing down of several thicknesses on each other.

Observations —The form of the colonies of this species seems to be
similar to those of Morania fragmenta (pl. 48) but their grouping is
quite different as they string out into long irregular masses while

230 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

M. fragmenta forms masses of definite outline; many of these
resemble long slender worms broken up and flattened out and smeared
over the shale, while others are definite in outline; the irregular
appearance is also increased by the presence of trails of small anne-
lids that evidently sought the floating algae and went to the bottom
with it.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

MORANIA FRAGMENTA, new species
Plate 48, figs. 1, Ia

Plant mass (colony) free as far as known, irregularly circular,
oval or elongate, and from 0.75 to 2 mm. in diameter when flattened
on the surface of the shale; these smaller bodies are grouped in
circular, elongate, and variously outlined clusters that were appar-
ently held together in a mucous or gelatinous matrix. The clusters
average about 3 to 5 mm. in diameter and occur widely scattered
over the surface of the shale or they may form relatively thick masses
about the carapace of a crustacean * as though they had been gathered
on the bottom by an eddy in the water; these circular groups vary
in size from 5 to 20 cm. and may include torn fragments of Morania
confluens. The impression made by the examination of a large
number of specimens is that the small colonies formed balls or
globose masses of varying shape held together by a mucous or
gelatinous matrix and that when flattened out they formed disks,
circular, oval, elongate or broken and irregular in outline ; the larger
number of specimens represent broken masses, hence the specific
name fragmenta.

Observations —This_ species differs from others referred to
Morania by having the small colonies united in groups to form
irregular masses that average 3 to 5 mm. in diameter.

In external form the colonies of M. fragmenta resemble the
living Nostoc sphaericum Vaucher (pl. 53, fig. 1) ; they appear to
have floated free in the water both singly and in groups held together
by a mucous or gelatinous matrix.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge

‘Usually Hymenocaris or Hurdia.

NO. 5 MIDDLE CAMBRIAN ALGAE 231

between Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass, above Field, British Columbia.

MORANIA ? FRONDOSA, new species
Plate 40, figs. 1, Ia

Only one specimen of this species has been found in the collec-
tions ; this is a portion of a large frond-like mass on the surface
of the shale that appears to have formed a thin membranous film
perforated by numerous more or less oval openings, lacunae, vary-
ing from I to 3 mm. in greatest diameter. It looks similar to the
thin gelatinous masses of Anabaena variabilis Kutzing (pl. 46, fig. 4)
as they appear when dried out on blotting paper. The latter species
often forms gelatinous scums floating on the surface of the water,
and it is very easy to imagine that a similar condition existed in the
case of M. frondosa.

The type and only specimen of this species is 11 cm. in length
by 6 cm. in width up to where a break in the shale cuts it off.

Observations—The only other form known to me from the
Burgess shale that in any way may be compared with M. frondosa
is M. reticulata, and only to the extent that both appear to have been
thin floating masses that dropped to the muddy bottom and left a
trace of their general form on its surface.

Formation and locality—Maiddle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

MORANIA ? GLOBOSA, new species
Plate 48, figs. 2, 2a-d

Plant masses (colonies) free as far as known, disk-shaped as
they occur flattened out on the shale but probably spheroidal or
elongate-globose before compression. The plant masses now appear
as dark, thin shiny membranous films, circular, oval or elongate-oval
in outline, with their surface mottled by irregular patterns of bright
silvery material. The specimens in the collection vary in size from -
13 mm. to 90 mm., and all appear to have been very delicate
gelatinous or mucous-like bodies with sufficient firmness of structure
to preserve their outline when compressed in the thin layers of mud
and to also wrinkle slightly by lateral compression; no traces of
strands comparable with those of Morania confluens (pl. 44, fig. 11)

232 SMITHSONIAN MISCELLANEOUS. COLLECTIONS VOL. 67

have been observed or lacunae perforating the frond; color and
microscopic structure unknown.

Observations.—This species is readily distinguished from the
globular or disk-shaped forms of M. confluens by regularity of out-
line, more delicate and thinner film on the shale and absence of
strands and lacunae; from M. costellifera it differs in its thin deli-
cate film, smooth surface and outline on the shale.

Among recent species, herbarium specimens of Nostoc prumforme
Agardh (pl. 53, fig. 2) resemble the delicate membranous disks of
M. globosa both in outline and smooth surface.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge be-
tween Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass, above Field, British Columbia.

MORANIA PARASITICA, new species
Plate 50, figs. 1,. 1a, 2

Plant mass (colony) free as such but in groups lying on and
attached to the smooth surface of the carapace of crustaceans and
that of the membranous film of Morania globosa. The individual
masses are about I mm. in diameter; they occur singly and in
irregular clusters or they may be so pressed together as to form a
continuous surface ; they were probably held together by a gelatinous
exudation from the colonies.

Observations —The first impression of this incrusting form was
that it represented masses of Moramia fragmenta (pl. 48) that had
become attached to, and spread irregularly over, the surface of
smooth objects; the small round disk-like masses are similar in
shape but after examining a large number of specimens I think we
may tentatively separate them as distinct from M. fragmenta.

The incrusting alga may occur scattered thinly over the surface
or cover it entirely; in no instance has it been seen to extend
beyond the edge of the crustacean carapace or membranous alga
on which it occurs. I thought that perhaps the incrusting form
might be a secondary deposit of mineral origin and asked Dr. George
P. Merrill of the United States National Museum to examine and
test it with this in view. He very kindly did so and reported as
follows: ‘The material giving the sheen to these fossil impres-
sions is not, as I had been inclined at first to think, of a metallic-
sulphide nature but is wholly untouched by acids, even aqua regia.

NO. 5 MIDDLE CAMBRIAN ALGAE 233

I am, therefore, inclined to regard it as of a carbonaceous or
graphitic nature. It cannot be due to an impregnation of liquid
hydrocarbon but rather to vegetable or animal growth and.con-
temporaneous with the shale.”

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

MORANIA ? RETICULATA, new species
Plate 52, figs. 2,.2a

This species, like M. frondosa, appears to have been in the form of
a gelatinous floating film that when pressed flat on the muddy bottom
left only a trace of its form; this indicates that the mass was per-
forated by numerous small openings, which give the surface the
appearance of an irregularly reticulated, slightly roughened, more
or less torn membrane that may be compared with herbarium
specimens of Anabaena variabilis Kiitzing (pl. 46, fig. 4).

Observations —The specimen illustrated has an irregular mass
of M. confluens attached to it.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

MARPOLIA, new genus

All that is known of this genus is described under the type species.

Genotype—Marpolia spissa Walcott.

Stratigraphic range—Middle Cambrian: Stephen formation;
Ogygopsis shale, on Mount Stephen; Burgess shale and superjacent
thin-bedded limestone, which give a vertical range of about 450 feet
(137.25 m.).

Geographic distribution—At Burgess Pass fossil quarry, in
Burgess shale, on western slope of ridge connecting Wapta Peak
and Mount Field, and on west slope of Mount Field one mile (1.6
km.) northeast of Burgess Pass above Field, also on northwest
slope of Mount Stephen above Field, British Columbia, Canada.

Observations —The second species, M. aequalis, apparently has a
definite axis and branches, which probably arises from the twisting
together of the filaments and their imperfect preservation ; fragments

234 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of M. spissa occur in the same beds which have the characteristic
shiny silvery appearance of W. aequalis.

MARPOLIA SPISSA, new species
Plate 52, figs. 1, 1a-b

Thallus formed of slender, flexuous branched filaments that, -
twisted together, form an irregular axis from which the filaments
extend in tufts or dense masses in the same general direction as they
branch at narrow angles; the form of the thallus appears to depend ~
upon how the floating mass of algae happened to settle on the surface
of the muddy bottom; often the czespitose tufts have been so com-
pletely torn apart that the shiny, silvery filaments nearly cover the
surface of the shale (fig. 1b); the filaments are marked by trans-
verse lines into sections a little longer than wide as in the living
Cladophora fracta (Vahl) Kutzing; the outer walls are slightly in-
dented opposite the transverse lines, but I have not been able to dis-
cover further details of structures.

The larger tufts average from 3 to 5 cm. in length, and may
spread out to 4 or 5 cm. at the top.

Microscopic structure unknown.

Observations.—This species is very abundant on several layers
of the shale either as tufts (figs. 1, Ia) or scattered filaments.
The plants were probably epiphytic, growing in tufts attached to
any object and from which they were readily detached by currents
or annelids and crustaceans moving about among them. The: form
of growth is somewhat similar to that of the living Cladophora
arcta (Dillw.) Kitzing, and C. gracilis (Griffiths) Kitzing (pl. 51,
hg. 1), and the transverse walls of the filaments are macroscopically
much like those of Cladophora fracta (Vahl) Kiitzing and some
species of Chaetomorpha, C. clavata (Agardh) Kiitzing, C. aerea
¢Dillw.) Kutzing; comparison should also be made for form with
Ectocarpus mitchellae Harvey, E. elegans Thuret, and Pylaiella
littoralis (L.) Kjellman.

Formation and locahty.—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass; and (14s) Ogygopsis zone of the Stephen
formation, at the great “fossil bed” on the northwest slope of
Mount Stephen, both above Field on the Canadian Pacific Railroad,
British Columbia, Canada.

NO. 5 MIDDLE CAMBRIAN ALGAE 235

MARPOLIA AEQUALIS, new species
Plate 55, fig. 1

Thallus a tuft of fine branching filaments that when twisted
together give the appearance of a central stem and strong branches ;
the filaments appear tobe a little larger than those of M. spissa, and
they are not as much flattened on the shale; traces of transverse
lines are clearly shown on some of the filaments. The one specimen:
referred to this species has a length .of about 4 cm.

Microscopic structure unknown.

Observations —This form is closely related to M. spissa (pl. 52) ;
it differs in being somewhat more robust and in its larger filaments.
It may be compared with the living Cladophora scopaeforimuis
(Ruprecht) Harvey in its robust habit of growth.

Formation and locality—Middle Cambrian: (14s) Ogygopsis
zone of the Stephen formation; about 2,300 feet (7oI m.) above
the Lower Cambrian and 3,540 feet (1,089 m.) below the Upper
Cambrian in the Ogygopsis zone of the Stephen formation, at the
great “fossil bed” on the northwest slope of Mount Stephen,
above Field on the Canadian Pacific Railroad, British Columbia,
Canada.

CHLOROPHYCEAE (GREEN ALGAE)
Genus YUKNESSIA, new genus

The description of the type species includes what is known of the
genus.

Genotype—Yuknessia simplex Walcott.

YUKNESSIA SIMPLEX, new species
Plate 54, figs. I, Ia-c
Thallus small, 2 to 3 mm. in diameter; main stem large, hollow,
and covered with closely arranged conical plates, each plate probably
forming the base of a long flexuous stipe that shows no evidence of

230 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

jointing, bifurcating or carrying branches; the stipes are slender
and form a thin shiny film on the shale; there does not appear to be
any terminal bifurcation, although on one specimen it is suggested
by the presence of two whorls of terminal branchlets of Dalyia
racemata (pl. 56).

Microscopic structure unknown.

Observations —I placed this form as a possible sertularian when
making a preliminary examination of the collection, but it shows
no structure warranting it nor is it closely allied to any recent
algae; some of the Codiaceae have a strong stem supporting a mass
of bifurcating branches, Penicillus and Rhipocephalus, but here the
resemblance ceases as the stipes of Ywknessia are unbranched and
the stem is covered with plates. Dr. Rudolph Ruedemann describes
a somewhat similar form from Ordovician, Trenton, limestone of
New York* which he placed tentatively with the algae; this has
a large plated stem, but the stipes are branched as in Penitcillus.

There are three well-defined specimens in the collection; one
shows a portion of the side of the main stem and the other two
the rounded top of the main stem with a number of stipes radiating
from it.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) northeast
of Burgess Pass, above Field,*British Columbia.

RHODOPHYCEAE (RED ALGAE)
Family RHODOMELACEAE
Genus WAPUTIKIA, new genus
All that is known of this genus is described under the type species.
Its geographic distribution and stratigraphic range are the same
as for the genus Morania (p. 225).
Genotype—Waputikia ramosa Walcott.

WAPUTIKIA RAMOSA, new species
Plate 54, figs. 2, 2a-b
Thallus consisting of a rather strong, somewhat flexuous central
stem or stipe with relatively strong branches springing from it at
irregular intervals; the primary branches give off short secondary

*New York State Museum Bull. 133, 1908, pp. 206-207, pl. 3, figs. 1-5.

NO. 5 : MIDDLE CAMBRIAN ALGAE 237

branches, which give rise to minor branches, and these again divide
into branches each having several slender filamentous branchlets
attached apparently to the outer side of the branch.

The largest specimen in the collection, which is probably a frag-
ment broken off from a large frond, has a length of 6 cm. with a
width of 3 cm.

The central stem and all branches have a black, smooth shiny sur-
face without traces of linear or transverse lines or markings and
resemble thin carbonaceous films.

Microscopic structure unknown.

Observations —The mode of branching of this species recalls the
genus Dasya of the Rhodophyceae, notably D. gibbesi Harvey (pl. 53,
fig. 3), which has a more slender stem and branches, but its terminal
filaments form foliage-like clusters that resemble those of Waputikia
ramosa to a surprising degree. The form of the stem and main
branches is somewhat similar to those of Euthora cristata (Linn.)
J. Agardh as shown by herbarium specimens.

When stripped of the terminal filaments the branches resemble
those of a branch of a deciduous bush without leaves.

This form is rare as only five specimens were met with in the six
years’ collecting at the Burgess Pass quarry.

DALYIA, new genus

The description of the type species includes practically all that
is known of the genus. —

Genotype —Dalyia racemata Walcott.

The other species referred to the genus is D. mitens, which
occurs in the same layer of shale with D. racemata.

Stratigraphic range-——Middle Cambrian: Stephen formation;
Ogygopsis shale, on Mount Stephen; Burgess shale and superjacent
thin-bedded limestone, which give a vertical range of about 450 feet
6147.25) m1).

Geographic distribution—At Burgess Pass fossil quarry, in
Burgess shale, on western slope of ridge connecting Wapta Peak and
Mount Field, and on west slope of Mount Field one mile (1.6 km.)
northeast of Burgess Pass above Field, also on northwest slope of
Mount Stephen above Field, British Columbia, Canada.

238 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

DALYIA RACEMATA, new species
Plate 55, figs. 4, 4a-b; plate 56, figs. I, Ia-c

Thallus formed of narrow slender stems or stipes 0.4 to 0.6 mm.
in diameter, branching from a simple central stem; the stems are
usually pressed flat and show only a smooth surface, but there are
a few that have traces of transverse lines, and one fragment of a
thallus has distinct transverse lines about a diameter of the stem
apart, giving it a jointed appearance, in this respect resembling the
stems of the living Halurus equisetifolius (Lightf.) Kiitzing; a
single branch may extend out at nearly a right angle to the central
stem, as one on each side, or there may be a grouping of three or
four radiating from the distal end of the central stem; the plain,
straight branches support at their distal end a whorl of stipes or
branchlets that vary in length from 3 to 10 mm., and these may also
have one or more short branchlets in a whorl of not to exceed five
short stipes, as now known. The largest thallus has a length of
about 4 cm. Microscopic characters unknown.

Observations —This species is moderately abundant in a more or
less broken up state in one layer of shale along with drifted fragments
of crustaceans ; it probably flourished in the waters near by and was
drifted along by gentle currents until the fragments found a resting
place on the muddy bottom.

Among fossil forms Callithamnopsis fructiosa (Hall) Whitfield *
has simple branches bearing terminal whorls of branchlets very
similar to those of D. racemata, but the general arrangement of the
branching is quite dissimilar.

Among living algae fragments of Griffithsia opuntioides J. Agardh
suggest the terminal branchlets of Dalyia racemata, but the branching
from the central stem is more like that of Carpomitra cabrerae
(Clem.) Kiitzing.

D.racemata differs from D. nitens in the attachment of the branches
to the central stem and in the form of the whorls at the end of the
branches.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
betwen Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, also (14s) Ogygopsis zone of the Stephen
formation; about 2,300 feet (701 m.) above the Lower Cambrian
and 3,540 feet (1,089 m.) below the Upper Cambrian, at the great

* Bull, American Museum Nat. Hist., Vol. 6, 1804, p. 354, pl. 11, figs. 4-8.

NO. 5 MIDDLE CAMBRIAN ALGAE 239

“ fossil bed” on the northwest slope of Mount Stephen, both above
Field on the Canadian Pacific Railroad, British Columbia.

DALYIA NITENS, new species
Plate 55, fig. 3

Thallus known only by a single specimen, consisting of a fragment
of the central stem, with two branches that are attached to globose
or pyriform enlargements of the main stem; the straight, slender
branches have a pyriform enlargement at the distal end that supports
a whorl of at least five slender branchlets or pinnules that do not
show in the specimen evidence of further division; the appearance
of the flattened stem suggests that it was hollow and of a carbon-
aceous nature. The fragment of the thallus preserved has a length of
I5 mm.

Microscopic characters unknown.

Observations —Among fossil forms this species may be compared
with the Ordovician species Callithamnopsis fructiosa Whitfield,
with respect to its slender branches with enlarged distal end and
whorl of branchlets ; the latter species does not have the enlargement
of the main stem where the branches arise, and its general aspect
is dissimilar. There does not appear to be any recent alga that
resembles this species in external appearance.

Genus WAHPIA, new genus

The description of the type species includes all that is known
of the genus.

Genotype—W ahpia insolens Walcott.

Geographic distribution—At Burgess Pass fossil quarry, in
Burgess shale, on western slope of ridge connecting Wapta Peak and
Mount Field, and on west slope of Mount Field one mile (1.6 km.)
northeast of Burgess Pass above Field, also on northwest slope of
Mount Stephen above Field, British Columbia, Canada.

* Bull. American Museum Nat. Hist., Vol. 6, 18904, p. 354, pl. 11, figs. 4-8.

240 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

WAHPIA INSOLENS, new species
Plate 57, figs. I, Ia

Thallus consisting of a long central stem with long slender branches
that spring from it at an angle of about 45°; these give rise to a
few minor branches of the same character. A second specimen has
four successive branchings with possibly a very delicate branching
at the end of the fourth member. The surface of the stem and
larger branches is marked by a strong median line with clearly
defined edges, which indicates that they represent hollow stems
flattened on the shale. Microscopic structure unknown.

The largest specimen has a total length of 8 cm.

Observations —Both of the two specimens found of this species
appear to be drift fragments from which most of the finer branches
have been broken off. W. insolens branches in a similar manner to
the recent marine algae Ahnfeldtia plicata (Huds.) Fries and Cysto-
clonium purpurascens (Huds.) Kutzing. A stem of the latter with
extensions of the branches broken off, resembles closely W. insolens.
Comparison should also be made with Ahnfeldtia concinna J. Agardh
and Gymnogongrus leptophyllus J. Agardh, which have a somewhat
similar form of branching.

WAHPIA MIMICA, new species
Plate 55, fig. 2

Of this species only one broken specimen of the thallus has been
found. The stem and branches are narrow, rigid, and have left
a strong impression on the shale; the primary branches are numerous
and alternate on opposite sides of the stem in their flattened condi-
tion; the secondary branchlets are also numerous and have the same
arrangement as the main branches; some of the long secondary
branches appear to bifurcate towards their distal end.

Microscopic structure unknown.

Observations —This form has several of the characters of Wahpia
msolens, but it differs in its more numerous branches and branchlets.
Its round stem and manner of branching strongly suggest the recent

NO. 5 MIDDLE CAMBRIAN ALGAE 241

Ahnfeldtia plicata (Huds.) Fries or Ceramium rubrum (Huds.)
Agardh. .

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

WAHPIA VIRGATA, new species
Plate 57, fig. 2

This species differs from W. insolens and W. mimica in having a
larger proportional central stem and more flexuous branches and
branchlets. The mode of branching and flexuous branches and
branchlets may be compared with the recent species Ceramium nitens
J. Agardh.

BOSWORTHIA, new genus
All that is known of this genus is described under the type species.
Its geographic distribution and stratigraphic range are the same as
the genus Morania (p. 225).
Genotype—Bosworthia simulans Walcott.

BOSWORTHIA SIMULANS, new species
‘Plate 57, fig. 3; plate 58, fis: 15) Da
Thallus formed of flexuous, membranous branches decompoundly
branched to a limited degree and with two or three narrow branchlets
near the extremities of the larger branches; as flattened out on
the shale the stipes vary from 2.5 mm. in width to 0.5 mm. at the
outer ends; the thin membranous ribbon-like stipes were evidently
easily folded, twisted and sprawled on the surface of the mud, or
the thallus may have been compact and when pressed flat in the
laminations of the muddy sediment the stipes were matted down on
each other; only traces of the carbonaceous matter remain on the
specimens.
The thallus known to us has a length of 8 cm. and a width of
3.5 cm. ; it narrows at the base as though attached to a central stem at
the base, and also narrows slightly towards the top.

242 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Observations.—Of this form only two specimens have been found ;
one of them (pl. 58, fig. 1) shows the branches grouped closely and
matted down on each other, and in the other (pl. 57, fig. 3) they have
been spread out and more or less displaced as though a portion of
the thallus had been torn off and drifted along by the current.

Among living algae Dumontia filiformis (Huds.) Greville (Rhodo-
phycea) has a somewhat similar form of growth, and possibly some
species of the Phaeophyceae, Dictyota ciliata J. Agardh and D.
fasciola (Roth) Lamour. may be compared with B. simulans. The
recent species have similar flexuous, membranous stipes that branch
in nearly the same manner. Among fossil forms Polyaedictyota
ramulosa (Spencer)* of the Silurian has a somewhat similar form
of growth and appearance.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

BOSWORTHIA GYGES, new species
Plate 58, fig. 2

Thallus formed of delicate ribbon-like branches rising from a
central base and forming a compact frond-like mass on the shale;
the branches as flattened on the shale are about 1 mm. in width
and the branching is obscured by their close grouping; the one
specimen known of the species has a length of about 3.25 cm.

Microscopic structure unknown.

Observations.—This species differs from B. simulans in its -com-
pact thallus and less flexuous branches. It adds one more species
to the relatively rich plant life of the Burgess shale and seems to
be worthy of recognition.

CALCAREOUS ALGAE
Genus SPHAEROCODIUM Rothpletz

Sphaerocodium RorHp etz, 1890, Bot. Centralbl., vol. 41, p. 9.

*See Whitfield, Bull. American Mus. Nat. Hist., Vol. 16, 1902, p. 399, pl. 53,
figs. I, 2.

NOS MIDDLE CAMBRIAN ALGAE 24

SPHAEROCODIUM ? PRAECURSOR, new species

% Plate 50, figs. I, Ia-c

This species occurs as a very small free thallus as shown by
transverse sections found in thin sections cut from the Burgess shale.
The exterior walls have been destroyed by solution and replaced by
a mass of fine calcite crystals (figs. 1, 1a-b). The interior of the
mass is filled with sections of what were probably irregular tubes
that have been obscured and often destroyed by the recrystalliza-
tion of the mineral matter of the original structure. The convolu-
tions of the tubes appear to have been short and without any
recognizable arrangement in the sections available for study.

Measurements.—The larger masses are from 0.6 mm. to 1.75 mm
in diameter with tubes about 0.01 to 0.015 mm. across.

Observations —This species is represented by larger specimens
than Sphaerocodium ? cambria and its tubular structure is also
coarser and less definitely arranged; its structure may be compared
with that of S. munthei Rothpletz* (pl. IV, fig. 4) but owing to
its imperfect condition none of the finer details can be determined.

Formation and locality——Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, one mile (1.6 km.) north-
east of Burgess Pass, above Field, British Columbia.

SPHAEROCODIUM ? CAMBRIA, new species
Plate 50, fig. 2

This is a microscopic form the thin sections of which show
numerous fine, irregularly arranged tubes that resemble those of
S. gothlandicum Rothpletz.” The thallus and tubes are much more
minute than those of S. praecursor.

Dimensions.—The type specimen is broken off along the mar-
gins—it is approximately 0.0255 mm. across; the tubes are about
0.0006 to 0.0008 mm. in diameter.

Observations —Only one specimen of this species has been located
in the slides although several were seen in a preliminary examination
of slides when a locating and measuring stage was not available.

* Sveriges Geol. Unders., Ser. Ca, No. 10, 1913, p. 10, pl. 4, figs. I, 2.

244 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL,

DESCRIPTION (OF sPLATRE 43

MorANIA CONFLUENS Walcott (See pls. 44, 45 and 58)....................
Fic. 1. (X90.) Strings of round, cell-like bodies formed of pyrite
and broken strings of smaller and similar bodies; cubes
of pyrite are scattered in the thin rock slide, which is

photographed by transmitted light. (Slide No. 25.)

2. (x 200.) Still further enlargement of strings of cell-like.

bodies formed of pyrite. (Slide No. 81.)
3, 3a. (XX 1,000.) A few scattered balls of pyrite, some of which
show in outline a botryoidal appearance. (Slide No. 81.)
4. (xX 400.) A broken chain of round cell-like bodies. (Slide
No. 81.)

5. ( X60.) A flexuous chain crossed at the lower end by a frag-

ment of a chain. (Slide No. 96.)
6. (X 250.) Enlargement of the lower end of the chain repre-
sented by fig. 5.

The chains and balls represented by the above-described figures
occur in thin rock sections cut on the plane of flattened specimens
of the alga Morania confluens (See pls. 44, 45) as it occurs on the
surface of the shale.

The specimens represented on this plate are from locality 35,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 5, PL. 43

CHAINS AND BALLS ASSOCIATED WITH MORANIA CONFLUENS Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS

MORANIA CONFLUENS Walcott

NO. 5 MIDDLE CAMBRIAN ALGAE 245
DESCRIPTION OF PLATE 44

PAGE

MoRANIA CONFLUENS Walcott (See pls. 43, 45, and 58)..........-..cce00- 226

Fics. 1 and 2. (Natural size.) Two small groups or colonies that
were held together by a gelatinous mass which now forms
a film on the surface of the shale. U. S. National

Museum, Catalogue Nos. 35378 and 353790.
3 and 4. (X2.) Small, irregular and somewhat thicker films
than those represented by figs. 1 and 2. U. S. National

Museum, Catalogue Nos. 35380 and 35381.
5. (X2.) Portion of a membranous frond that has been dis-
torted and torn. U. S. National Museum, Catalogue

No. 35382.

6. (Natural size.) Several small plant masses that have been
flattened down together on the shale, some of which
have the outlines shown by figs. r and 2. U. S. National
Museum, Catalogue No. 35383.

(Natural size.) Another group of small plant masses with
one on the upper side that appears to be Morania ? cos-
tellifera. (See pl. 47, figs. 1, 2.) U. S. National
Museum, Catalogue No. 35384.

8. (Natural size.) An irregular plant mass with part extended

on the shale. U. S. National Museum, Catalogue
No. 35385.

9. (<2.) A small plant mass similar to that represented by

fig. 8, with what may have been an annelid trail extend-
ing down from it. U. S. National Museum, Catalogue
No. 35386.

10. (2.) Fragment of a plant mass with lacunae extending
through it. U. S. National Museum, Catalogue No.
35387.

Ir. (X3.) Portion of a large plant mass that has been later-
ally compressed so as to give it an irregularly finely
wrinkled surface. U. S. National Museum, Catalogue
No. 35388.

All of the specimens represented on this plate are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railway, British Columbia, Canada.

246 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 45

MoRANIA CONFLUENS Walcott (See pls. 43, 44, and 58)..............0.00- 226
Fic. 1. (X 4.) A torn, irregular fragment of a large plant mass with
numerous lacunae. The surface is striated or finely
wrinkled longitudinally by lateral compression. U. S.
National Museum, Catalogue No. 35380.
1a. (Natural size.) A fragment of a gelatinous-appearing plant
mass with numerous lacunae. U. S. National Museum,
Catalogue No. 35390.

The specimens represented on this plate are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railway, British Columbia, Canada.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

MORANIA CONFLUENS Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 5, PL. 46

RECENT ALGAE

1. Nostoc commune Vaucher

2. Nostoc verrucosum (Linn.) Vaucher
3. Nostoc parmeloides Vaucher

4. Anabaena variabilis Kutzing

NO, 5 MIDDLE CAMBRIAN ALGAE 247
DESCRIPTION OF PLATE 46

PAGE

Nostoc COMMUNE Vaucher........ PM cic c SMES ete Ue SOROS uma Seem cits 228

Fic. 1. (Natural size.) Fragment of a plant mass flattened by pres-
sure, for comparison with the fossil form Morania con-
fluens (fig. I, pl. 45).
1a. (Natural size.) A plant mass with unbroken auphees flattened
by pressure, for comparison with the fossil forms of
Morania confluens (figs. 1-5, pl. 44) and M. ? globosa
(figs. 2, 2a-c, pl. 48).

Nostoc veRRucosuM (Linn.) Vaucher.......... Lian d2e, 229
Fic. 2. (Natural size.) Portion at. a | ine a mass, “daitened by pres-
sure, that has a finely wrinkled surface similar to that of
some fossil specimens of Morania confluens (fig. 11,
pl. 44).

ANKE Ome MIM ETL ONIN SER TIEZAINID co cayetstaty states osake vis 3 Sse 'dieicaw leieis, q elovaieve dialare coe epee 229
Fics. 3, 3a-d. (Natural size.) More or less circular plant masses,
flattened by pressure, that suggest the fossil form
Morania costellifera (figs. 1, 2, pl. 47).
3e-g. (Natural size.) Broken and irrégular plant masses that
may be compared in form with the fossil Morania frag-
menta (fig. 1, pl. 48).

NCABINEINCAD VARDABIENS: CtItZIM O's, « cil siedi cle, visle aisle’ sia veep sic «els else cles ces 228, 231
Fic. 4. (Natural size.) Plant mass flattened on paper. The lacunae
and mode of spreading out suggest the fossil forms,
Morania confluens (fig. 1, pl. 45), M. frondosa (fig. 1,
pl. 49), and M. reticulata (fig. 2a, pl. 52).
4a. (Natural size.) A more dense mass of this species.

All of the figures on this plate are reproductions of photographs
of specimens of recent algae in the National Herbarium at the
Smithsonian Institution.

248 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 47

MoRANIA COSTEELIFERA, Walcott. ©. oc1s « cfeiete 016 cleleieie cuelereistsein/= eles tet eneane 229
Fics. 1 and 2. (X3.) Two specimens showing sharp wrinkles of
costae which have given the name to the species. U. S.
National Museum, Catalogue Nos. 35391 and 35302.

MoRANIA:. ELONGATA: Walcott: ...0 occ 6.060 tcc oe 0+ seis ec cretelatcletsiete hetenT 220
Fic. 3. (Natural size.) Portion of a specimen as it appears on the
shale. U.S. National Museum, Catalogue No. 35393.
3a. (4.) Enlargement of the central portion of the specimen
represented by fig. 3, illustrating the general appearance
of the species.

The specimens représented on this plate are all from locality 35k,

‘ Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railway, British Columbia, Canada.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Morania ? costellifera Walcott

2.
3, 34. Morania elongata Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS

1. Morania fragmenta Walcott
2. Moranla ? giobosa Walcott

NO. 5 MIDDI.E CAMBRIAN ALGAE 249
DESCRIPTION OF PLATE 48

PAGE

DRUM SGAE MER VV ANCOLE. ot Fo cu cecatees ccaddeedccaeceuecacaccestce 230

Fic. 1. (Natural size.) <A typical illustration of this species as it
occurs on the surface of the shale. U. S. National
Museum, Catalogue No. 35394.
1a. (X4.) A portion of the specimen represented by fig. 1, en-
larged to show the character of the fragments.

SE TOBOIA OMY ULCER och a nie) eric a,c he tvpem dois ena ajee sta ecw eee cece
Fic. 2. (Natural size.) A specimen flattened on the shale and show-
ing only a thin gelatinous appearing film. U. S. National
- Museum, Catalogue No. 35395.
2a. (X2.) A still more gelatinous appearing specimen than that
represented by fig. 2. U. S. National Museum, Catalogue
No. 35396.
2b. (Natural size.) A small round specimen resembling that illus-
trated by fig. 2. U. S. National Museum, Catalogue
No. 35397.
2c. (xX 3.) Enlargement of the specimen represented by figure 20.
2d. (X2.) A distorted specimen which may be one of the smaller
plant masses of Morania confluens. U. S. National
Museum, Catalogue No. 35398.

The specimens represented on this plate are all from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railway, British Columbia, Canada.

231

250 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 49

MoRANIA ? FRONDOSA Walcott... ..c0.ccce. cone cess scl cine arene 231
Itc. 1. (Natural size.) Portion of the frond described in the text.
U. S. National Museum, Catalogue No. 35399.
1a. (X2.) Enlargement of a portion of the specimen represented
by fig. 1, to illustrate the lacunae.

MorRANIA Species undetermined... 00002020200. 00-0 + see eee eee
Fic. 2. (Natural size.) Fragment of what may have been an unde-
termined species of Morania. U.S. National Museum,

Catalogue No. 35400.

The specimens represented on this plate are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above -
Field, on the Canadian Pacific Railway, British Columbia, Canada.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 49

1. Morania frondcsa Walcott
2. Morania sp. undt.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

MORANIA PARASITICA Walcott

NO. 5 MIDDLE CAMBRIAN ALGAE 251

DESCRIPTION OF PLATE 50

Mein EAA STRTICAC NW AlGO EUS siteraie bicieicistei nie elslaltintaiclars <4 dsisiu,s esis cWlew sie'e's' b's 232
Fic. 1. (Natural size.) A specimen of Hurdia victoria* more or less

encrusted with this species. U. S. National Museum,
Catalogue No. 57718.

Ia. (X 3.) Enlargement of a portion of the surface of the speci-
men represented by fig. 1.

2. (X3.) Portion of a specimen of Morania ? globosa encrusted
with this species. U. S. National Museum, Catalogue
No. 35401.

ca Smithsonian Misc. Coll., Vol. 57, 1912, p. 186, pl. 32, fig. 9.

252 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION: OF (PLATE 51

CLADOPHORA GRACILIS’ (Griffiths) Ktitzing.. 2.0.2.6 05 «oss oes sce 234
Fic. 1. (X2.) Portion of a plant mass spread and flattened on a
card, for comparison with the fossil form, Marpolia
spissa (figs. I, 1a-b, pl. 52).

DuMONTIA FiItiFORMIS ‘((Huds.) Greville. . 0. 0.00s ox cen os tee ee hee 242
Fic. 2. (Natural size.) Portion of a plant opened and pressed flat
on a card for comparison with the fossil form Bosworthia
simulans (fig. 1a, pl. 58).
All of the figures on this plate are reproductions of photographs
of specimens of recent algae in the National Herbarium at the
Smithsonian Institution.

PL. 51

VOL. 67, NO.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

RECENT ALGAE
Cladophora gracilis (Griffith) Kitzing

2. Dumontia filiformis (Huds.) Greville

ile

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 67, NO. 5. PL. 52

1. Marpolia spissa Walcott
2. Morania reticulata Walcott

NO. 5 MIDDLE CAMBRIAN ALGAE 253

DESCRIPTION OF PLATE 52

MARPOLIA SPISSA Walcott ........0.sseecececeeesecees OSA Ati eae 234
Fic. 1. (X2.) Portions of a thallus with the filaments twisted into

stems and extending as tufts as they branch at narrow
angles. U.S. National Museum, Catalogue No. 35403.

Ia. (X2.) A specimen with the filaments more loosely arranged
than in fig. 1. U.S. National Museum, Catalogue No.
35404.

1b. (X4.) Enlargement of a portion of the surface of a frag-
ment of shale that is thickly strewn with broken filaments
of this species. U. S. National Museum, Catalogue
No. 35405.

Sen aeE MCORP BIG UEAT SUNY AICOtEs aig dics css ee ooo de kin n sce cedcededace cdencee 233
Fic. 2. (Natural size.) A frondlike mass of this species partly cov-
ered by Morania confluens. U. S. National Museum,
Catalogue No. 35402.
2a. (X 4.) Enlargement of a portion of specimen represented by
fig. 2, to illustrate the lacunae of the frond.

The specimens represented on this plate are all from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railroad, British Columbia.

bo
unr
Bh

DESCRIPTION: OF -PLATEHss3

Nostoc¢ SPHAERICUM Vaucher. .. 7%... ccs. secsem selene: oa eee
Fic. 1. (Natural size.) A group of plant masses, flattened on a card,
for comparison with the smaller specimens of the fossil
species of Morania ?” globosa (fig. 2b, pl. 48), and when

broken, with Morania fragmenta (figs. 1, 1a, pl. 48).

NOSTOG ERUNIFORME Clinn:)) Agardht .2..-c.~ ree scien eee
Fic. 2. (Natural size.) Two plant masses flattened on a card that
resemble very closely similar circular films of the fossil

species Morania globosa (figs. 2, 2a, 2c, pl. 48).

DASVA GIBBESID FLArVey. v.65. cle ote sia etic ose aete neperetete oeweleeie aie eee
Fic. 3. (2.) Portion of a plant flattened on a card, for comparison
with the fossil species Waputikia ramosa (fig. 2, pl. 54).
3a. (X2.) Portion of a stem for comparison with the stem of
the fossil species Waputikia ramosa (fig. 2b, pl. 54).
All of the figures on this plate are reproductions of photographs

of specimens of recent algae in the National Herbarium at the
Smithsonian Institution.

SMITHSONIAN MISCELLANEOUS COLLECTIONS - VOL. 67

232

237

— a |

VOL. 67, NO. 5, PL. 53

SMITHSONIAN MISCELLANEOUS COLLECTIONS

RECENT ALGAE
1. Nostoc sphaericum Vaucher
2. Nostoc pruniforme (Linn.) Agardh
3. Dasya gibbesii Harvey

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 67, NO. 5, PL. 54

’

Yuknessia simplex Walcott
Waputikia ramosa Walcott

No-

NO. 5 MIDDLE CAMBRIAN ALGAE 255

DESCRIPTION OF PLATE 54

YUKNESSIA SIMPLEX Walcott.............. Se frat oS ac au ew eta
Fic. 1. (X2.) Type specimen flattened on the shale. U. S. National
Museum, Catalogue No. 35406.
Ia. (X3.) Sketch of specimen illustrated by fig. 1.

The specimen represented by figs. 1, 1a is from locality 14s,
Middle Cambrian: Ogygopsis zone of the Stephen formation;

about 2,300 feet (701 m.) above the Lower Cambrian and 3,540 feet:

(1,089 m.) below the Upper Cambrian, at the great “fossil bed”

on the northwest slope of Mount Stephen, above Field on the:

Canadian Pacific Railroad, British Columbia.

1b. (X3.) The upper portion of a small specimen showing the

radiating stipes. U. S. National Museum, Catalogue
No. 35407.

Ic. (X4.) Stipes radiating from the summit of the central body
of a relatively large specimen. U. S. National Museum,
Catalogue No. 35408.

rue e Mar dE WOES VALCO. 2 Sic a clas’ bie we aluyalvio wiclelseweocsedeeceeesses
Fic. 2. (X2.) A flexuous stem with branches illustrating the appear-
ance of the plant when pressed flat on the shale. U. S.
National Museum, Catalogue No. 354009.
2a. (X3.) Fragment of a small stem and main branches that
have been stripped of the secondary branches and branch-
lets. U. S. National Museum, Catalogue No. 35410.
2b. (X2.) A central stem with branches partly stripped of the
secondary branches and branchlets. U. S. National
Museum, Catalogue No. 35411.

The specimens represented by figs. 1b, Ic, 2, 2a-b are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railroad, British Columbia.

236

256 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 55

PAGE

MARPOLIA AEQUALIS, Walcott.:. o3...s:c006 ns s00%e «es nae.e steleigienile penne 235
Fic. 1. (X2.) An elongated tuft of branching filaments, portions of
which twisted together give the appearance of a central
stem and branches. U. S. National Museum, Catalogue

No. 35412.

From locality 14s, Middle Cambrian: Ogygopsis zone of the
Stephen formation; about 2,300 feet (701 m.) above the Lower
Cambrian and 3,540 feet (1,089 m.) below the Upper Cambrian, at
the great “fossil bed” on the northwest slope of Mount Stephen,
above Field on the Canadian Pacific Railroad, British Columbia.

WaAHPIA MIMICA Walcott... ac ccs sic con cise csieiele nin on ids 6 te eer 240
Fic. 2. (X2.) Type specimen illustrating stem and form of branches.
U. S. National Museum, Catalogue No. 35413.
DALYIA NITENS' ‘Walcott s). dokiin he with itietee sicle eicielee oct eee ee 239
Fic. 3. (XX 3.) Central stem with branches and whorl of branchlets at
the end of each. U. S. National Museum, Catalogue
No. 35414.
DALYIA RACEMATA Walcott (See pl. 56) «2.0.20 04¢ «0's sx nels bo ete eee 238

Fic. 4. (X 4.) Whorl of branchlets that may belong to this species.
U. S. National Museum, Catalogue No. 35415.
4a. (X3.) Branches and whorls of branchlets that may belong
to this species, but more probably indicate a distinct
form. U.S. National Museum, Catalogue No. 35416.
Ab. (X3.) A fine branch showing variation in form from those
i represented on plate 56, U. S. National Museum, Cata-
logue No. 35417.

The specimens represented’ by figs. 2-4, 4a are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
on the Canadian Pacific Railroad, British Columbia.

4c. (X3.) <A specimen of this species occurring in the Mount
Stephen fossil bed, 3 miles (4.8 km.) in an air line from
the Burgess Pass quarry. U.S. National Museum, Cata-
logue No. 35418.
From locality 14s, as given above under fig. I.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 6

pow

Marpoiia aequelis Walcott
Wahpia mimica Walcott
Dalyia nitens Walcott
Dalyla racemata Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS

DALYIA RACEMATA Walcott

NO. 5 MIDDLE CAMBRIAN ALGAE 257

DESCRIPTION OF, PLATE 56

DY ATEMIAGRAGHEMUATAL WV AlCOLt (S€@ PlieS5)). ccc cccnecee eect nescsceseeeenes 238
Fic. 1. (X2.) <A group of stems with branches and whorls enlarged

on a smaller scale than the specimens represented by
figs. 1a, 1b, and 1c. U.S. National Museum, Catalogue
No. 354109.

la, 1b. (X3.) Specimens illustrating variation in the mode of
branching. The center upper stipe of fig. Ia results,
I think, from the pressing together of a number of short
branchlets. This tendency is shown in fig. 1c. U. S.
National Museum, Catalogue Nos. 35420, 35421.

1c. (X 4.) Specimen with closely grouped branchlets on the ter-
minal whorls which suggest the specimen illustrated by
fig. 4, pl. 55. U.S. National Museum, Catalogue No.
35422.

258 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PATE Ss;

WAHPIA INSOLENS Walcott: oss. cv ecaicss sicverave stole cle aie bevel oiayeteree ee eee
Fics. 1, 1a. (Natural size.) Two specimens flattened on the shale,
illustrating the mode of branching. U. S. National

Museum, Catalogue Nos. 35423, 35424.

From locality 14s, Middle Cambrian: Ogygopsis zone of the
Stephen formation; about 2,300 feet (7or m.) above the Lower
Cambrian and 3,540 feet (1,089 m.) below the Upper Cambrian, at
the great “fossil bed” on the northwest slope of Mount Stephen,
above Field, on the Canadian Pacific Railroad, British Columbia.

WAHPIA VIRGATA, Walcott .<.o cvsie0 sc.0 sisueeiec coleloieyele oh eatceei rete eae
Fic. 2. (XX 3.) Type specimen of the species. U.S. National Museum,
Catalogue No. 35425.

BOSWORTHIA SIMULANS Walcott (See pl. 58, fig..1).. <. Sac. ..0 . ose eee
Fic. 3. (xX 2.) Illustration of the flexuous branches pulled apart and
pressed flat on the surface of the shale. U. S. National

Museum, Catalogue No. 35426.

The specimens represented by figs. 2 and 3 are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railroad, British Columbia.

241

— ae

SMITHSONIAN MISCELLANEOLIS COLLECTIONS

1. Wahpia insolens Walcott
2. Wahpia virgata Walcott
3. Bosworthia simulans Walcott

NO. 5, PL.

VOL. 67,

simulans Walcott

Bosworthia

ba
°
2
$
i)
®
re]
>
)
AJ
<=
Pe
a.
°
3
”
°
a)
nN

3. Morania confiuens Walcott
4. Morania with trilobites

SMITHSONIAN MISCELLANEOUS COLLECTIONS

NO. 5 _ MIDDLE CAMBRIAN ALGAE 259
DESCRIPTION OF PLATE 58

PAGE

BoswoRTHIA SIMULANS Walcott (See pl. 57, fig. 3)...........ceeeeeceeees 241

Fic. 1. (X2.) <A specimen illustrating the probable outline of the
thallus when occurring in a compact form. U. S. Na-
tional Museum, Catalogue No. 35427.
1a. (Natural size.) Specimen illustrated by enlarged figure on
pl. 57, fig. 3. U. S. National Museum, Catalogue No.
35426.

EXO URED AMC! CHS) AI COLD sat ok sisicve mi ciete wicisls siv'el cleeie cise sjejg 6 es atv iee cous ses
Fic. 2. (X2.) Type specimen illustrating the form and mode of
growth of this species. U. S. National Museum, Cata-

logue No. 35428.

MoraANIA CONFLUENS Walcott (See pls. 43, 44, 45, and 58)...............-
Fic. 3. (X 3.) Portion of the surface of a frond showing fine strands
and wrinkles. U. S. National Museum, Catalogue No.

35429.

MIORANUDAMIIIC HE EHODILES act. ss cic deleten cle os c's evalsluisters cles coersiv cieisie bc cui cod. e
Fic. 4. (X2.) The upper trilobite (Oryctocephalus reynoldsi Reed)
is resting on a piece of Morania, and the lower trilobite
(Ptychoparia) is covered with a thin layer of it as de-
scribed in the text. U. S. National Museum, Catalogue

No. 35430.

242

226

260 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION, OF PLATE cp

SPHAEROCODIUM:# PRAECURSOR Walcott. «icc else eile sm ieerelere eerste teen
Fics. 1 (X 73) and ta. ( X85.) Thin sections across the thallus of
two small specimens. The outer wall is replaced by a
narrow band of calcite crystals that extend somewhat
irregularly into the sponge and the irregular tubular
structure fills in the entire central space. Slide No. 79.
1 is located on stage at 101.5-++-43; Ia on stage at
102 + 48.2. U.S. National Museum, Catalogue No. 35431.
1b. (x 365.) Further enlargement of a portion of the thallus on

the leit side of the specimen represented by fig. 1.
Ic. (X 500.) Enlargement of a portion of specimen in slide
No. 78, located on stage at 109+ 43. U. S. National

Museum, Catalogue No. 35431.

SPHAEROCODIUM, CAMBRIA” Walcott... 50. «+c egies «ve actin «ace
Fic. 2. (X 1200.) A minute thallus showing the ends and oblique sec-
tions of the twisting, irregularly distributed tubes. Thin
rock slide No. 45, located on stage at 105.5-+- 39. U. S.

National Museum, Catalogue No. 35432.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL 67, NO. 5, PL. 69

1. SPhaerocodium ? praecursor Walcott
2. Sphaerocodium ? cambria Walcott

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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 6

CAMBRKIAN
GEOLOGY AND PALEONTOLOGY

IV
No. 6.—MIDDLE CAMBRIAN SPONGIAE

(WiTH PLATES 60 To 90)

BY
CHARLES D. WALCOTT

(PUBLICATION 2580)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
1920

+ The Lord Baltimore Dress
BALTIMORE, MD., U.S. A.

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CAMBRIAN GEOLOGY AND PALEONTOLOGY

IV
No. 6—MIDDLE CAMBRIAN SPONGTAE

By CHARLES D. WALCOTT
(WitH PLates 60 TO 90)

CONTENTS
PAGE
NGM CCGE TO Timer rarer stores leo «cane RP TGReas Weysceyc taht tom alc afechel scl aareminete re 263
elt ataemcetne rate ties ciara.e ssi co REMI Po a ears eetexero Seteshis.@ Sian a een tte 265
(Gemenaue dil Gsm eGleSpia sats 4c. < cee anes nes aie tite eieioeibis «acc fMRI ese 265
Comparison wath recent SPONSES my. cs cine otis caisiielc wis ale sil, sie goed Derisies 267
Comparison with Metis shale sponge fauna .....................-00- 267
WESCuIp i TOlMOlSPECIESE Vane cle...» shiketeterte oie nui cieoinais Nici sanclaleccieacloree 269
SSA ler SOMAEESOTERAG: ... . Cigdenacifac’s & eclya oon.c ore dos) cigar bn ode 8 4 vhslele e's 269
Order Monactinellida Zittel (Monaxonidae Sollas) ............. 269
Subs-Order Ealichondrimay W OSIMaer .,.%. ssc ced oe ss 06s ve od ants 269
Ealichondsttes! Daw soneaecn cise sani cis & cleicicks « adie oa anls 269
Halichondrites elissa, new species.................. 270
AM POmtar IEW. -O CNS UN cence ci siren ein ae Ske bee bane eB 271
Tuponia~ lineata mew Species... )..%-.0. 2.6660 .% - 272
Tuponia bellilineata, new species .................. 274
Puponia. fexiligantew Species v2.00 6 snes c wee sche e s 275
Tuponia flexilis var, intermedia, new variety ........ 276
Ae eel cl SINC W MEMCRIIES ce ceca aya toa fel anemia «sae Sends aks 277
Gakakkawia lineata, New Species’... ... 42... .s5052. 277
Wie pias wine CM USmR Euan eetinoce Soir conchae. s 279
Wapkia-erandiqmmew Species. 00). 0. ae. 2s.'s co oe eee 279
Etazelian mew seers meme eure ort te eter ovorstron bos cecioces, oe ere 281
Tdazelia palmate, SPECIES £2 occcsc. oda cecsa sca ce 282
Elazeliacontertay mew Species’... -...206c205- eee ss 283
Hazeliasdelicatula, new species: .2...2s4.22.-css oss. 284.
Hazeliay ® erandisuiew SPeCles. -mseck ssn esee ok ec 285.
Hazelia mamimillatas mew. Species) «2... ..4..ccac as ee: 286:
HazeliamodtulifteraamewsSpecies:..... = os54-1o0.0 2 287
Elazeliavobsclitawnewe SpeClesiocgun sence seine ce ek ass 287
Gralla. sie W> Sel testa tats te ectie ia eae eeersle hae 46 sass 288
Corcahasundulataynewespecies seins deen. s400) 3 <. 288:
Seueimelin, mew Genesee eee ciate eewacesc aia sedans « 5 280
Sentinelia draco, NEW SPECIES . ... bs, esc waco suse 290

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 6
261

262 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Family. Stberitidaes © in. «s-ct-m Sa tee 1G Ree ee ee re
Chola, Rew Pens yee. 1550) econ ee Se ee a ee 291°
Chola ‘carteri, new Species: \.2 oo e so eee 292
Choia-ridleyi; mew species (2.50... ene oe 204
Choia ttahensis, ‘new species.....;:2....7.)/2,92. ee 205
Chota hinder (Dawson), 64.00: Secs 205
Hamptonia;, new Penus, «4: Sens. sack ac eee 2096
Hamptonia bowerbanki, new species ............... 207
Pitania, new. SenUSy2% «sce Nhe ce le ee 2098
Pirania muricata, ‘new species. ........1.s00..eeeeeee 298
Order Hexactinellida O. Schmidt (Triaxonia F. E. Schulze).... 301
Stib-Order: Lyssacina Zittel . 2 ...05 caus hoenek fe ee 301
Family: Protospongidae: Hinde J. .).<. ..< 4.) s20s0eeeeeee 301
Protespongia Salter .. 153.15... ov. kb oe eee 301
Protospongia: erixo, mew species. -.....2... se 353
Protospongia fenestrata Salter ....2. 42. -4eeee 304
Protospongia hicksi Hinde ... %....2...s.e2ee 307
DiagoniellaRauit. 22.02.05 652s cade ea 309
Diagoniella hindei, new species ................ 310
Kiwetinokia, new genus... .2...<).2.. Ua. See 311
Kiwetinokia utahensis, new species ............. 313
Kiwetinokia spiralis, new species ............... 314
Kiwetinokia metissica (Dawson) .............. 315

Sub-Order. Dictyonina Zittel 2s. 0.00.0 2 sone cing ae 31
Family Vauxininae,new family .. 2.04... 0.us oe eee 316
Vauxia, Dew Pens 2.25.0 40. oe so. bs fem eRe ee 317
Vauxia gracilenta, tlew. Species 2 3:..0cses. eee 318
Vauxiaybellula, newaspecies 4-65 se ac eee 320
Vauxaa densa, new Species. wc. cs. ee sete 320
Vatixia dignata, new Species. o..+-.sese cnn 321
Viattxia (2)! venata, mew species) 4.024 ee eee 322
Bamily.©Octactinellidae, Hinde sascha aeeeereeeeeee 322
Hiffelia, Mew GENUS «6.0 nwisi es - ale cose anes oe
Bittelia elobosa, new SPeCles aaaccie> clea 324
Sub-Order Heteractinellida Elinde ye. 4. sacle eet 325
Family Chancelloridae, new family ............2.-s8een 327
Chancellonian mew emis)... sce serene 327
Chancelloria eros, new species ............cses 320
Chancelloria drusilla, new species ........+ seen 331
Chancelloria libo, mew species ...............- 332
Chancelloria yorkensis, new species ............- 332

ILLUSTRATIONS

PLATES FACING

PLATES PAGE
60, 61. Halichondrites elissa Walcott ........ "hai aaa nicl yorkie eo ae eee 334, 335
62,635 uporniat lineatas Walcott erorme ree ee ner ee tees 336, 337

64. Tuponia flexilis intermedia Walcott and Tuponia bellilineata Walcott. 338
65. Puponiac fexrlis:) Walcott: wins. sueeeatin eae ee ee soiallale cae ene 39839

No. 6 MIDDLE CAMBRIAN SPONGIAE 263

Geno7 bo. Wyapiia orandis: . WalGQtey ils. ssivecsccleletcthieus osc ciclels 340, 341, 342
Gomblerzeliamnalnmc tama Vial COtby <emieperaneises s.ctoisiar-retsi cc’ oS cle ice se Mepis g eusisio% 343
edt eal se cc itliel NV LCOUE rere tate eicce acel dis dice clase ofa Se so pete cs Fae cleid nucas 344
71. Hazelia obscura Walcott, Hazelia ? grandis Walcott, and Hazelia
ALO CBE HAN ALGO ULE eyesore ree Perey voter ttc tears erase Choe aie lel nce ie aiete tndioroies 345
72. Sentinelia draco Walcott, Corralia undulata Walcott, Hazelia con-
fertoamVValcotands Choiaucanteni: Walcott 2csic. tho6c <cie.seeien eee tes ae 346
FamiChoiascarten! Walcott and Chor ridleys Walcott .........ccees60- +. 347
PA Oiame Gt dilevimevValcOtt «si. saint « oe Bla rertolenils ero hse 8 0.5% oleae sica seis 348
75. Choia utahensis Walcott and Choia carteri Walcott .................. 349
76. Choia hindei (Dawson), Hazelia palmata Walcott, and Hamptonia
eYanymerclorehalseroN AVC} ee CoRR onc, cocac hs Gee aCe Can Oat eae ne eRe Ie A aA Si eee 350
aml AimpLOniaeDOWEenbAtikt, VWielkcottie sojaccscc teres cic leis e's w)e.6 tears oes 251, 352
79. Pirania muricata Walcott and Protospongia erixo Walcott........... 353
80. Protospongia fenestrata Salter and Protospongia hicksi Hinde .... 354
81. Diagoniella hindei Walcott and Vauxia dignata Walcott .............. 355
' 82. Vauxia bellula Walcott and Vauxia gracilenta Walcott .............. 356
OSA Alixctaye La ClleMtanVVAlCOLE.. «1s cestinreya acy hae aetsle Slateyere obo sic © acer clan ercisse 357
SAMVGATERTCERGE TIS ASM VAL COLE... ..< cotter teeta cleo sratererovem «i ciere 0 jefe cuonesernicles« 358
SEMA titclan (Gro) me VeTIA AEN Vell COLE “cepacia sisi cricle aie io aucle file erercieyeneral cic) o myerel eters 359
86. Eiffelia globosa Walcott and Chancelloria eros Walcott............. 360
87. Chancelloria libo Walcott, Chancelloria drusilla Walcott, Chancelloria
yorkensis Walcott, and Takakkawia lineata Walcott............... 361
88. Chancelloria eros Walcott ..... ae eee a ARE Ne) Sac athena: 362

89. Kiwetinokia utahensis Walcott and Kiwetinokia spiralis Walcott .... 363
90. Tuponia lineata Walcott, Hazelia delicatula Walcott, and Hazelia
mmevanrranaileyiay WWEICO NE Ba Gtgoiioc 166 nob Goethe GoOaed ConooouUDbDUUeD DoUt 364

TEXT FicurES
FIGURES

need EAN aides ate Aoi eed VY ALCOUL. 5 Gafipercss todevafese fe 2 Xictsss/548 S/o bcusieldin 4c ofedu s woeielate 209
RaOearatasponeia mononetia Dawsait sc. ..<..c<c nc ssesrecedce cece ws nces 303
Pol aacoiiella, cyatnitormis MAWSON: ¢can-ns.s on'ss ole vce dete calsucewa Ss 309
Se merino idia: metissica( DawSGmy) sri beer caeles comtce celee ee eceus 316
OMA Ea Or ACI erabam VV Ak COEE siasa: ss semen tere oases esis atcha ceclcubtes cna aie aid lo Dldve wie else 319
Repel An ONOSAN NV ALE OPE. cc ctc's.sifeebenctaieiete ales iera oe Riels sedveiaiaysre ten a's 4-006 Slane oye 324

INTRODUCTION

The sponges of the Burgess shale member of the Stephen formation
of the Middle Cambrian of British Columbia comprise nearly all of
the siliceous sponges known to me from Cambrian strata of America.
Dr. G. F. Matthew has described a number of minute forms from the
Cambrian rocks of New Brunswick that he has referred to the
Spongiae.* All the species described are represented by minute

*Trans. Royal Soc. Canada, Vol. VII, 1890, pp. 148-150. Trans. New York
Acide, Val, SUV, 1865) pp. 112, 113:

264 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

specimens in an unsatisfactory condition of preservation. With brief
descriptions and diagrammatic illustrations, and only a hurried glance
at the material fifteen years ago, I do not think I can comment upon
the generic references of the several species named. Matthew de-
serves great credit for the results he secured from the fragmentary
and poorly preserved Cambrian material of New Brunswick, but his
work will require careful revision with the type specimens before
many of the more obscure forms can be satisfactorily identified and
classified.

Dr. J. G. Bornemann* has described cylindrical stems that are
simple, branching and anastomosing, that occur in the Cambrian
rocks of Sardinia, as a sponge analogous to the living Axinella.” He
named it Palaeospongia prisca, gave a detailed description with many
illustrations, and considered it probable that many so-called fossil
algae such as Palaeophycus might be sponges somewhat similar to
Palaeospongia.

The small spherical form from the Upper Cambrian described by
Walcott as Haguia sphaerica’ is probably a sponge, but in its present
condition of preservation all traces of spicules have disappeared
owing to the crystallization of the calcite ; it must await the study of
the American Archaeocyathinae and allied forms before a decision
can be made.

There is also the Lower Cambrian Sponge Leptomitus zitteli Wal-
cott,, which strongly resembles small specimens of Tuponia lineata
Walcott described in this paper (see pls. 62, 63). The long longi-
tudinal spicules are similar, and there appears to have been a compact
dermal layer in which fine, short, simple spicules occur. It may be
that better specimens of Leptomitus would show a structure similar
to that of Tuponia, in which case the latter name would be a synonym
of Leptomitus, which is now referred to the order Monactinellida.

There were probably many other forms of siliceous and calcareous
sponges of which only a few traces have been found. My object in
this paper is to call attention to the sponges from the Burgess shale
and to leave to future investigation the collecting of material and
study of the sponges of the Cambrian.

1 Die Versteinerungen des Camb. Schichtensystems der Insel Sardinien, Pt. 1,
1886, pp. 22-27, pl. 3, figs. 1-3, pl. 4, figs. 1-3.

* Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, p. 178.

®> Monogr. U. S. Geol. Surv., Vol. LXIII, Pt. II, 1899, p. 442, pl. LXIII,
figs. 6, 6a.

* Bull. U. S. Geol. Survey, No. 30, 1886, p. 89, pl. 2, figs. 2, 2a. Tenth Ann.
Rept. U. S. Geol. Survey, 1890, p. 507, pl. 40, figs. 1, Ia.

No. 6 MIDDLE CAMBRIAN SPONGIAE 265

Habitat—The sponges found in the Middle Cambrian Burgess
shale, like the algae, were probably carried into the Wapta pool by
currents, as they are widely scattered in the shale and are not forms
that would flourish in muddy water. A description of the habitat and
mode of deposition of the Burgess shale fauna is given on page 219
of this volume in connection with the description of the associated
algal flora.

Manner of Preservation—The sponge spicules and dermal layers
are usually replaced by pyrite or coated with a thin black film.

The mode of occurrence of the sponges at Little Metis led Sir. J.
W. Dawson to the following conclusions :*

Originally rooted in the soft ooze of the sea bottom the specimens seem
sometimes to have been buried im situ, so that when the shale is split they
appear in transverse section or as round flattened discs; but in most cases
they seem to have drifted from their anchorage, either with or without their
anchoring-rods, and to have been flattened laterally. When entire, they some-
times present, when the shale is split open, a surface of dermal spines, masking
the skeleton proper. In other cases the dermal spines come away with the
matrix, leaving the skeleton spicules exposed. Thus the same species may
present very different appearances under different circumstances. In most
cases the body of the sponge has been more or less disintegrated or reduced
to patches of loose spicules, and some large surfaces are covered with a con-
fused coating of spicules and anchoring-rods belonging to several species.
In some cases also the loose spicules, or fragments of them, seem to have
been gathered in little oval or cylindrical piles and inclosed in pyrite. At
first I was disposed to regard these as coprolitic; but Dr. Hinde doubts this,
and regards them as merely loose spicules drifted together into hollows or
wormburrows.

Genera and species—The classification is mainly that of Zittel
with a few additions on account of forms unknown to him. The fol-
lowing genera and species are described in this paper:

Sus-CLaAss SILICISPONGIAE

Order Monactinellida Zittel
Sub-Order Halichondrina Vosmaer
Genus Halichondrites Dawson

Halichondrites confusus Dawson
Halichondrites elissa Walcott

Genus Tuponia Walcott
Tuponia bellilineata Walcott
Tuponia flexilis Walcott
Tuponia flexilis var. intermedia Walcott
Tuponia lineata Walcott

* Trans. Royal Soc. Canada, 2d ser., Vol. 2, Sec. IV, 1896, p. 90.
* Text Book of Pal., Eastman, 2d ed., 1913.

266

Genus
Genus

Genus

Genus
Genus

Family
Genus

Genus
Genus

Order
Sub-Order
Family
Genus

Genus

Sub-Order
Family
Genus

Family
Genus

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

Takakkawia Walcott
Takakkawia lineata Walcott
Wapkia Walcott
Wapkia grandis Walcott
Hazelia Walcott
Hazelia conferta Walcott
Hazelia delicatula Walcott
Hazelia ? grandis Walcott
Hazelia mammillata Walcott
Hazelia nodulifera Walcott
Hazelia obscura Walcott
Hazelia palmata Walcott
Corralia Walcott
Corralia undulata Walcott
Sentinelia Walcott
Sentinelia draco Walcott
Suberitidae
Choia Walcott
Choia carteri Walcott
Choia flabella (Hicks)
Choia hindei (Dawson) sp.
Choia ridleyi Walcott
Choia utahensis Walcott
Hamptonia Walcott
Hamptonia bowerbanki Walcott
Pirania Walcott
Pirania muricata Walcott
Hexactinellida O. Schmidt
Lyssacina Zittel
Protospongidae Hinde
Protospongia
Protospongia erixo Walcott
Protospongia fenestrata Salter
Protospongia hicksi Hinde
Diagoniella Rauff
Diagoniella hindei Walcott
Kiwetinokia Walcott
Kiwetinokia metissica (Dawson)
Kiwetinokia spiralis Walcott
Kiwetinokia utahensis Walcott
Dictyonina Zittel
Vauxininae Walcott
Vauxia Walcott
Vauxia bellula Walcott
Vauxia densa Walcott
Vauxia dignata Walcott
Vauxia gracilenta Walcott
Octactinellidae Hinde
Eiffelia Walcott
Eiffelia globosa Walcott

No. 6 MIDDLE CAMBRIAN SPONGIAE 267

Sub-Order Heteractinellida Hinde °
Family Chancelloridae Walcott
Genus Chancelloria Walcott

Chancelloria drusilla Walcott
Chancelloria eros Walcott
Chancelloria libo Walcott
Chancelloria yorkensis Walcott

Comparison with recent sponges—The Monactinellid sponges of
the Burgess shale form a group that has little outward resemblance
to many sponges of this Order. This is particularly true of the
genera Halichondrites, Tuponia and Takakkawia as they more nearly
resemble such Hexactinellid forms as FEuflectella and Holascus.
I have repeatedly examined the Cambrian specimens referred to the
Monactinellida for traces of Hexactinellid spicules but without
success.

In forms of growth and the arrangement of the dermal spicular
layer Hazelia is suggestive of Pachychalina and Rhaphidophlus,’
but the main skeletal strands are more like those of the Hexactinel-
lida.

Choia (pl. 73) has the same general form and type of skeletal
structure as Trichostemma sarsii Ridley and Dendy’ from off the
Azores, and the Australian seas.

There is considerable range of variation in the species of both
fossil and living genera in size and form.

Among the Hexactinellids of the Cambrian there are none that
have a close resemblance to living sponges. The branching form of
Vauxia (V. gracilenta) may be compared in this character with the
genus He-actinella,’ but the resemblance is only superficial.

None of the sponge remains clearly suggest the presence of the
Horny Sponges (Ceratospongia), although if present they might
have been preserved in the Burgess shale. The external appearance
of species of Hagelia and Vausxia may be compared with that of the
Ceratospongian genera Thorecta and Stetospongia, but there is
nothing more known on which to base a comparison and possible
identification.

Comparison with Metis shale sponge fauna—We find in the
Burgess shale five genera that occur in the Metis shale, Halichon-
drites, Choia, Protospongia, Diagoniella, and Kiwetinokia, and three

1Rept. Voyage H. M. S. Challenger, Zool., Vol. XX, 1887, pp. 19-25, 151-155,
pls. 4, 5, 6, 28, 29, and 46.

? Idem, p. 218, pl. XLIII, figs. 1-4.

*>Idem, Vol. XXI, 1887, pls. 93, 94.

268 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

that have not been seen in the Burgess shale. There are two elongate
conical forms referred to Cyathophycus and Acanthodictya, a large
Protospongia-like form referred to the genus Palaeosarcus Hinde,
and some fragments placed under Lasiothrix Hinde.” Of the forms
not common to the Burgess and Metis shale only two have special
significance as indicating a different phase of development of the
Hexactinellida. These are Cyathophycus quebecense Dawson’* and
Acanthodictya hispida Hinde. Both of these forms suggest Cya-
thophycus reticulatus Walcott * of the Ordovician Utica shale, a form
that apparently is not represented in the Burgess shale.

The stratigraphic position of the Metis shale is given by Dawson
as probably in the lower member of the “ Quebec group” * or
“Lower Ordovician or later Cambrian age.’’*® In addition to the
sponges a brachiopod has been found in the Metis shale, which I
have identified as Acrotreta sagittalis (Salter).’ Dawson identified
this species as Obolella (L.) pretiosa Billings,’ but at the time he was
apparently unacquainted with the type of that species which is an
Acrothele or with Acrotreta sagittalis (Salter). (Compare figures
of the latter species on plate 71, Mongr. 51, Pt. II, U. S. Geol. Sur-
vey, with those of Acrothele pretiosa on pl. 58 of the same memoir.)
A. sagittalis occurs in both the Upper and Middle Cambrian and
when discussing it in 1912 I said, “ The Acrotreta (by error Acro-
thele in text) is a Middle Cambrian type, and nothing similar to it is
known from the Upper Cambrian (should have been Chazy). As far
as this shell (4. sagittalis) can locate the horizon, it is Cambrian,
and probably low down in the Upper Cambrian, if not in the Middle
Cambrian.” * I have not obtained any further data since 1913 and
must leave the question of the exact horizon of the Metis shale fauna
for further investigation with the comment that both the sponges and
the brachiopod point to the Cambrian age of the fauna.

*See Dawson, Trans. Royal Soc. Canada, 2d ser., Vol. 2, Sec. IV, 1896, pp.
IOI-I2I.

* Idem, p. 109, figs. 18, 19, p. 110; figs. 20, 21.

* See Mem. Pal. Reticulate Sponges, Hall and Clarke, 1808, Dh i

*Idem, p. 97.

°Idem, p. 121.

° Monogr. U. S. Geol. Survey, No. 151, 1912, p. 705.

“Idem, p. 119.

® Idem, p. 705.

No. 6 MIDDLE CAMBRIAN SPONGIAE 269

DESCRIPTION, OF SPECIES
Sub-Class SILICISPONGIAE

“Skeleton composed either exclusively of siliceous elements, or of horny
fibres enclosing siliceous spicules.”

Order MONACTINELLIDA Zittel
(MONAXONIDAE Sollas)

Monactinellid spicules are abundant in thin sections of some
portions of the Burgess shale and there are several species of which
we have more or less of the skeletons that appear to belong in the
Monactinellida. There are included in the genera Halichondrites
Dawson and Tuponia, Takakkawia, Wapkia, Hazelia, Corralia, Sen-
tinelia, Choia, Hamptonia, and Pirania described by Walcott in this
paper.

The sponges of this order undoubtedly existed during Upper
Cambrian and Ordovician time, as they occur in the Middle Cam-
brian and are met with in the Silurian as Climacospongia Hinde from
Tennessee, and their skeletal spicules are abundant in Carboniferous
and later rocks. As the largest group of recent marine sponges it is
important and interesting to find their representatives so well devel-
oped in Middle Cambrian time.

The Monactinellida (Monaxonida) is defined by Ridley and Dendy
in their great monograph on the Order as follows:

“ Siliceous sponges with uniaxial megasclera.”* (True skeletal
spicules of the Sponge, microsclera=minute scattered spicules.)

Sub-Order HALICHONDRINA Vosmaer

“Typically noncorticate; skeleton usually reticulate; megasclera usually
either oxea (straight spicules pointed at both ends) or styli (pointed at one
end and rounded at the other).?

HALICHONDRITES Dawson

Halichondrites DAwson, 1889, Trans. Royal Soc. Canada, Vol. VII, Sec. IV,
p. 52, text fig. 23. (Uses generic name and describes fragment of
spicular dermal layer.) Idem, 1896, 2d ser., Vol. II, Sec. IV, p. 116.
(Reprint of 1889 description and figure.)

Sir J. W. Dawson described fragments of the skeletal layer of a

sponge in which simple, elongate, acerate spicules cross each other

*Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, 1887, p. I.
* Idem, p. I.

270 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

obliquely to form an irregular elongate rhomboidal network. He
thought that these patches of fine spicules might indicate the presence
of a halichondroid sponge in the Little Metis sponge beds, and pro-
posed the generic name without description and gave the fragments
the name H. confusus. I found in the Burgess shale a large hali-
chondroid sponge, the dermal layer of which corresponds so closely
to the fragments described by Dawson that in the absence of further
means of comparison I include it in the genus Halichondrites and
use it as the type of the genus. The description of the species
FH, elissa includes all that is known of the genus.

Genotype.—Halichondrites elissa Walcott.

Stratigraphic range——H. elissa is found in the lower 10 feet
(3.05 m.) of the Burgess shale.

FH. confusus occurs in a narrow band of the Metis shale which is of
Cambrian and possibly Middle Cambrian age.

Geographic distribution.—H. elissa is found on the western slope
of ridge connecting Wapta Peak and Mount Field, 1 mile (1.6 km.)
northeast of Burgess Pass, above Field, British Columbia.

Hf. confusus occurs on the shore of the St. Lawrence River at Little
Metis, Province of Quebec.

HALICHONDRITES ELISSA, new species
Plate 60; fig: i; pl.AGrs figs. 1. sta. .

Sponge elongate, tubular in form.

Reticulum.—tLong, slender rods formed of hairlike spicules the
rods are in a right and left slightly oblique perpendicular arrange-
ment so that they cross each other at a narrow, sharp angle; they are
held together by a mass of fine acerate spicules that cross them
obliquely and at all angles; buried in this confused mass there is
a very fine, rectangular mesh’ with openings 0.5 mm. square, that
presumably is formed of small acerate spicules; the long rods are
formed of very fine threadlike spicules that are slightly interwoven
in places but they may be parallel; they were presumably held
together by fibrous connective tissue; flattened in the shale they
average about 0.5 mm. in diameter.

The best preserved specimen of this sponge is broken off 12 cm.
from what appears to have been the summit of the body, which as
flattened has a diameter of 5.5 cm.; from the upper rim the long rods
project directly upward from 3 to 5 cm.; at the upper border of the
body the minute acerate spicules appear to be embedded in a mem-
brane ; most of them cross each other obliquely to form a dense mass

NO. 6 MIDDLE CAMBRIAN SPONGIAE 271

and they extend upward beyond the rim, while others are transverse
or else more or less oblique to the vertical; over the surface of the
body of the sponge there is the same fine spicular membrane which
completely covers the large rods towards the top of the body and
appears to have covered them everywhere before the membrane was
removed by the splitting of the matrix from the surface of the
sponge.

Observations—The general form of the sponge is similar to
that of the Ordovician Cyathophycus reticulatus Walcott, but the
spicular structure is quite different. The long slender vertical rods
undoubtedly decreased in number towards the base and probably
a number of them formed an anchoring rope or strand as in the
‘Hexactinellid sponge Holascus fibulatus Schulze,’ the semispiral ar-
rangement of the rods and their crossing each other obliquely gave
strength to the siliceous spicular outer wall which was bound together
by a very fine outer spicular membrane. The long slender rods are
scattered over the surface of the shale near the body of the sponge
as well as a few fragments of the fine dermal membrane. A second
sponge is represented near the type specimen by a large fragment a
part of which rests on the latter (pl. 60) ; just what their relations
were it is difficult to determine owing to the manner in which they are
matted together. The body of the type specimen probably had a
length of 15 or 20cm., with a diameter at the upper end of about 4 cm.
This general form is somewhat similar to that of Cyathophycus
quebecensis Dawson.”

There is one fairly well preserved specimen in the collection and
three fragments, one of which indicates a considerably larger body
than the one described.

TUPONIA, new genus

Elongate, cylindric thin-walled sponge, with its skeleton formed of
vertical, slender spicular rods, with very fine transverse, simple

+See Rauff, Palaeontographica, Vol. 40, 1894, pl. 2, fig. 1.

* Rept. Voyage H. M. S. Challenger, Zool., Vol. XX1, 1887, p. 87, pl. XVI,
fig. Oo.

* Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 1889, p. 44, fig. 16.

272 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

spicules dividing the space between the vertical spicules into quad-
rilateral spaces of varying proportions.

Genotype.—Tupomia lineata Walcott.

Stratigraphic range—T. lineata is found in the lower 10 feet
(3.05 m.) of the Burgess shale, and Tupomia bellilineata occurs in
the Mount Whyte formation, about 250 feet (75.75 m.) below the
top of the Lower Cambrian and about 2,170 feet (661.85 m.) below
the Burgess shale.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Burgess
Pass, above Field; also at the railroad tunnel 3 miles (4.8 km.) east
of Field, British Columbia. ;

Observations —Tupomia differs from Halichondrites Dawson in
the manner of arrangement of the vertical and transverse spicules
and in its form. Both the vertical and transverse spicules are
embedded in a thin membranous dermal layer which has not shown
other forms of spicules. There are no indications of a double wall
such as occurs in the Dictyospongide’* or in Cyathophycus. The
dermal layer or integument appears to have included the entire wall.

The identified species are:

Tuponia bellilineata Walcott
Tuponia flexilis Walcott
Tuponia lineata Walcott

TUPONIA LINEATA, new species
Plate 62, figs. 1, 1a-b; pl. 63, figs. 1, Ia-c

General form slender, elongate, cylindric and tapering gently
towards the upper and lower ends; all specimens have been pressed
flat in the shale, the evidence of their original cylindric form being
the configuration of the upper end with its fringe of fine acerate
spicules about the osculum(?) and the presence on some specimens
of two distinct layers of the outer wall which represent the opposite
sides of the tube; the tube-like form was somewhat flexible as it is
found gently curved and partly contracted in places along its length
but it was more rigid than T. flexilis.

Surface smooth and shiny except for the fine striation resulting
from the presence of longitudinal spicules ; the surface appears to be

*Mem. Pal. Reticulate Sponges, Family Dictyospongidae, 1898, Hall and
Clarke, Albany, N. Y., p. 72.
? Idem, p. 23-25, pl. I.

No. 6 MIDDLE CAMBRIAN SPONGIAE 273

that of a parchment-like more or less flexible film in which the
spicules were embedded.

Reticulum.—The spicular skeleton is formed of a series of vertical
rod-like spicules that when not crowded together are from 0.5 to I
mm. apart; single spicules have been traced for a distance of 12
cm., and the larger are about 0.1 mm. in diameter; a central canal
is indicated in the larger spicules by a narrow channel along
the center of some of them; a number (3 to 5) of long, very
fine, vertical spicules occur between the main ones on well-preserved
specimens ; the very delicate transverse spicules are long and cross
beneath or inside of the main vertical spicules; they are usually
so completely embedded in the dermal surface that their presence is
indicated only by faintly defined lines; they outline a transversely
quadrilateral space between the main vertical spicules that is crossed
by the fine vertical secondary spicules. At the upper end both the
primary and secondary vertical spicules extend above the edge of the
tube to form a dense fringe and there are also some small irregular
tufts of very slender, short acerate spicules. The vertical spicules
may be parallel to the axis of the tube for a long distance or they
may be slightly spiral and cross each other diagonally so as to form
narrow rhombic spaces somewhat similar to those of Halichondrites ;
on one specimen the vertical spicules are parallel for 21 mm.; on
another 36.5 cm. in length they are parallel the greater portion of the
length and obliquely cross each other more or less toward each end
(fig. I, pl. 62); a few spicules appear to have escaped from the
regular vertical series and cross obliquely without regard to the
position of any of their associates. The lower end of the tube
terminates in a short fringe of fine spicules.

The extreme thinness of the walls is shown by specimens where
two sponges have been pressed down obliquely on each other; in
such the main vertical spicules of the underlying sponge show clearly
on the surface of the one above it as the result of having been im-
pressed through its walls; fine examples of Halichondrites-like
structure are thus formed.

Dimensions.—A specimen 36.4 cm. in length has a width as flat-
tened on the surface of the shale of 6 mm. at the upper end, 14 mm.
half way of its length, and 5 mm. near its base; it is contracted for a
short distance to 6 mm. in width 14 cm. from its base. The probable
diameter of this specimen when uncompressed was 4 mm. at the top,
9 mm. midway, and 3.5 mm. at the base. That this species grew to
considerable size is proven by the presence of a portion of a large

274 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

sponge 18 cm. in length and 3 cm. in width as flattened on the shale,
or about 2 cm. in diameter in a natural condition; it probably had a
total length of from 70 to 80 cm. when entire.

Observations.—This remarkably slender, elongate tube-like sponge
is a rather rare form in the Burgess shale ; that one specimen should
have been drifted into the deposit and found entire is most fortunate.
It probably grew on a soft bottom with the base more or less buried
in the sediment as there are no anchoring spicules of sufficient length
to have supported so long a body. The closely allied species, T. flex-
tlis, has a very slender base and may have had anchoring spicules.
The differences between the two species are given under T. fle-xilis.

Sir William Dawson noted in the Little Metis sponge fauna
“Groups of extremely simple straight spicules lying close together
and parallel or more or less disturbed. They are narrow, and may
have been cylindrical. One group has four long anchoring rods
arranged in two pairs. They show no indications of cruciform
spicules.” * The above description applies quite closely to fragments
of Tuponia lineata and suggests the presence of the genus Tuponia
in the Metis shale.

TUPONIA BELLILINEATA, new species
Plate 64, figs. 2, 2a-b

General form elongate, expanding very gradually upward.

Reticulum.—Fine vertical subparallel strands about 0.16 mm.
across and usually 0.5 mm. distant from each other extend from
where the frond is broken off below to the summit; they increase by
branching at a very slight angle, and do not either undulate to any
appreciable degree or inosculate; the interspaces between the main
strands are crossed transversely by very narrow strands about
0.4 mm. in diameter and 0.8 mm. apart; the transverse strands may
cross two or three of the vertical strands and interspaces and term-
inate, which causes a slight irregularity in the vertical position of
the rectangular spaces between the main vertical strands and also to

* Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 1880, p. 53, fig. 25. Dr. Daw-
son subsequently referred this fragment to the genus Stephanella Hinde with a
question mark. Idem, 1896, 2d ser., Vol. 2, sec. IV, p. 117.

No. 6 MIDDLE CAMBRIAN SPONGIAE 275

the ladderlike appearance of the spaces between each two vertical
strands; owing to the condition of preservation the individual
spicules have not been identified.

Fragments of the dermal layer remain on portions of the surface,
showing it to have been dense and slightly roughened; spicular
structure unknown.

Dimensions.—The only specimen in the collection has a length of
43 mm. with a width of 26 mm. at the top and 16 mm. where it is
broken off ; if it tapered to the base at the same angle its full length
was about 105 mm.

Observations.—Of this species there is a single specimen, collected
from a fine arenaceous shale of Lower Cambrian age. Its strati-
graphic position is about 2,500 feet (762.5 m.) below the Burgess
shale in which the other species of the genus Tuponia occur. It
differs from T. lineata in the greater regularity of its vertical skeletal
strands and transverse strands which divide the skeleton into ladder-
like spaces; whether it had a long slender base similar to that of
T. flexilis is unknown.

Formation and locality—Lower Cambrian: (58q) Mount Whyte
formation; about 250 feet (76.25 m.) below the top of the Lower
Cambrian in gray siliceous shale (102 feet=36.6 m.) forming 5
of Mount Whyte formation, Mount Stephen section; just above the
tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of
Field, British Columbia, Canada.

TUPONIA FLEXILIS, new species
Plate 65, figs. I, 1a-d

This species differs from T. lineata in having a flexible rope or
strand-like form of growth.

Reticulum.—tThe main vertical spicules are more numerous and
closer together and the secondary vertical spicules more clearly
defined ; the transverse spicules are exceedingly fine and obscure but
present in the smallest cross sections of the strand where the struc-
ture can be determined; no cruciform spicules have been found in
association with this species except those clearly belonging to the
species referred to Protospongia hicks.

Dimensions.—The largest specimen is a fragment 15 mm. across
at right angles to the vertical spicules; all the rope-like specimens
decrease very slightly in diameter ; one 4 mm. in diameter decreases
to 1.5 mm. in a distance of 14 cm., and another 35 mm. in length has
an almost uniform width of 1.5 mm.; a rope-like strand curved in a

276 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

narrow U and with both ends broken off has a length of 21 cm. with
a width of 6 mm. at the large end and 2.5 mm. at the smaller end; a
number of the smaller specimens are shown by figures 1a, Id, plate
65, which is a very good illustration of size and form.

Observations.—One specimen (fig. 1b, pl. 65) suggests that the
sponge was a hollow tube or cylinder open at the top as in T. lineata.
The oblique arrangement of the vertical spicules in portions of nearly
all the specimens also indicates a cylindric form of growth.

At first I considered these strand-like sponges to be anchoring
ropes of a large sponge, but on examining them closely and finding a
double series of spicules crossing at right angles and the long vertical
spicules running obliquely across so as to give strength to the
assumed cylindric structure, this view was abandoned in favor of its
being a sponge allied to Tupomia lineata.

Dr. Hinde®* illustrates the anchoring rope of a sponge which he
refers to Hyalostelia fasciculatus McCoy from the Cambrian, that
resembles some specimens of this species, but the bundles of rod-like
spicules are quite different in their arrangement.

TUPONIA FLEXILIS var. INTERMEDIA, new variety
Plate 64, figs. I, ta-b

This form combines characters of both 7. flexilis and T. lineata.
The upper portion appears to have been a cylindric tube that grad-
ually expanded from its base to the top without the contraction seen
in T. lineata towards the summit. A specimen 15.5 cm. in length
has a width of 14 mm. (as flattened) at the summit and 4 mm. where
it is broken off at the base. The lower 8 cm. is flexuous with the
vertical spicules crowded together as in T. flexilis, while the upper
portion is similar to the spicular skeleton of T. lineata except that it
is finer and tufts of minute simple spicules occur along its propor-
tionally broader upper margin; obscure transverse spicules occur in
the same manner as in T. lineata on the upper portion and as in T.
flexilis on the lower part.

This form is placed as a variety of 7. flexilis owing to its gradually
tapering from top to base and its fine crowded vertical flexed
spicules and less rigid form than that of T. lineata.

* British Fossil Sponges, Pt. 1, 1887, pl. 1, fig. 3.

No. 6 MIDDLE CAMBRIAN SPONGIAE 2a

Formation and locality —Middle Cambrian: (35k). Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field, on the Canadian Pacific Railway,
British Columbia.

Genus TAKAKKAWIA, new genus

Slender, cylindric, thin-walled sponge with its skeleton formed of
vertical strands of long spicules, with vertical bands of delicate
simple spicules embedded in spongin; fine transverse spicules occur
singly and in fine strands.

Genotype-—Takakkawia lineata Walcott.

Stratigraphic range-—Lower 10 feet (3.05 m.) of the Burgess
shale.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6km.) northeast of Burgess
Pass, above Field, British Columbia.

Observations —There is but one species of this genus. My im-
pression, when collecting it was that the sponge would fall within the
Hexactinellidae, but careful examination has thus far failed to show
anything more than simple spicules that appear to have been monacts
or diacts. It differs from Tupomia in form of growth and skeletal
structure, but it has the strong vertical spicules and fine transverse
spicules so characteristic of that genus.

TAKAKKAWIA LINEATA, new species
Plate 87, figs. 4, 4a-c

General form slender, elongate, cylindric and tapering gently to
a slender base and slightly contracted towards the upper end; the
tube was rigid and is rarely curved except in the upper half.

Reticulum.—The main skeletal elements are formed of long,
simple, slender spicules that are gathered into vertical strands con-
tinuous from their inception to the upper rim of the body; these
strands may be formed of two or three main spicules with several
very fine ones that may continue as part of the main strand or curve
out and terminate in the space between the strands; short spicules
also start in the strand and project beyond it so as to give a frazzled
appearance to parts of the strands; at the base there are several of
the long spicules closely pressed together into a rounded point that
is surrounded by a mat of extremely fine vertical spicules ; the main
spicules diverge and quickly gather as strands with spaces between

278 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

them; at about midway of the type specimen (fig. 4) there are eight
strands ; three of these merge into the adjoining strands as they near
the top; in some specimens the strands appear as though they had
been twisted so as to contract and expand several times in the course
of their length ; where the strands broaden out between the contracted
zones the enclosed space between the spicules is filled with a shiny
film similar to that of the narrow elongate bodies toward the sum-
mit of the sponge ; towards the summit of the body the main spicules
are merged into and obscured in a dense mat of fine vertical spicules
forming the vertical bands.

The vertical bands are strong and resist breaking up in a remark-
able degree; they have on each side one of the vertical strands
described above and in the interspace between the strands there is
a closely arranged series of vertical, very fine thread-like spicules,
crossed by irregularly spaced, fine transverse slender spicules either
singly or in strands so as to form quite regular quadrangular spaces
in some parts, and in others, especially the lower half of the body,
there are almost no traces of the transverse spicules; on several
specimens the interspaces of the vertical bands are divided obliquely
by imbricating, leaf-like, elongate oval-shaped masses of very fine
spicules; these have a definite outline and appear to form a layer,
distinct from the layer of straight, fine vertical spicules.

The vertical open spaces between the spicular bands appear in
some examples to have resulted from the splitting open of the body of
the sponge by compression, but in others there is no such indication
and a few fine transverse spicules cross from strand to strand and
sometimes across two or three spaces; we do not know the exact
number of vertical strands and bands; eight strands with nine bands,
one outside of the outer strand on each side, and one open space are
shown on one specimen. Toward the summit of the sponge shiny,
narrow elongate bodies pointed at the ends are arranged in a trans-
verse band with their longer axis parallel to the vertical axis of the
sponge ; they appear to be in pairs in the vertical bands and to pertain
to the inner wall as though they might have been arranged about the
osculum some distance within the upper end of the body.

The vertical bands are well preserved on a number of specimens ;
they appear to have been formed of spongin with numerous vertical
and oblique, very fine spicules, arranged at least in two layers.

Dimensions.—A sponge 42 mm. in length, flattened on the shale,
has a width of 7 mm. at the center, 5.25 mm. at the summit, and
I mm. near the sharply rounded base; the main spicules are about
0.16 mm. in diameter.

’

No. 6 MIDDLE CAMBRIAN SPONGIAE 279

Observations—What may be anchoring spicules occur in asso-
ciation with one specimen, but in the best preserved the lower end is
slender as though the sponge stood up with its end embedded in
the sediment. The presence of spongin is indicated by the very
definite outline of the vertical bands and their evident character
without the presence of a strong spicular structure. The spongin is
preserved as a shiny smooth surface that under the microscope is
resolved into a mass of minute crystals or points of pyrite. The
large spicules are also often coated with pyrite.

WAPKIA, new genus

Elongate-oval, flattened fronds with distinct compact walls.
Skeletal: frame work formed of monactinal or diactinal spicules in
a close, irregular net-work. Spongin indicated by firm surface and
outlines of sponge.

Genotype—Wapkia grandis Walcott.

Stratigraphic range-——Lower 10 feet (3.05 m.) of the Burgess
shale.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Burgess
Pass, above Field, British Columbia.

Observations —W apkia is related to Tuponia and Hazelia by its
mode of growth and spicular structure, but differs from Tuponia in
having a more compact and stronger skeleton and from Hazelia by
its transverse system of spicules. The description of the type
species presents the character of the genus and species as far as
determined.

WAPKIA GRANDIS, new species
Plate 66, figs. 1-3; pl. 67, fig. 1; pl. 68, figs. 1, 2, 2a

General form when flattened on the shale an elongate-oval, varying
in width and outline. There does not appear to be any distinct base
or point of attachment, although the fronds undoubtedly grew in an
upright position as is indicated by the arrangement of the spicules
(see pl. 66, fig. 1, and fig. 1, pl. 67). A double wall is indicated by
fig. 1, pl. 66, but whether the frond was thin or tube-shaped is not
readily determined ; it is probable that it was thin on the edges with

280 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.. 67

an oval, hollow, transverse section. From the evidence afforded
by seven well-preserved specimens both sides of the frond had the
same wall structure.

Reticulum.—tvThe skeletal elements include a well-developed, com-
pact reticulation of simple strands and sometimes branching spiculo-
fiber ; in addition there are long, strong spicules embedded more or
less in the walls, that are usually subparallel to the nearest outer
margin of the frond. The main lines of the skeleton starting from
what was evidently the lower portion of the frond branch upward
and curve outward toward the margins (fig. 1, pl. 67), where they
terminate in a fringe of fine, hair-like spicules; these main vertical
lines are crossed by a system of transverse lines or strands that are
often arranged in bands about 0.5 mm. apart extending outward
from a central vertical strand that appears like a stripe with the
transverse strands projecting at right angles from it (see fig. 2,
pl. 68); the transverse strands with the intermediate thread-like
spiculae terminate on the margins in an imbricating manner and ap-
pear like a fringe on the shale (fig. 1, pl. 68). “The fibrous strands
are formed of very delicate thread-like spiculae and styli that vary
greatly in length; they appear to extend into the strand and to also
mingle with the spicules of the interspaces between the main strands.

The spaces between the transverse and vertical strands are filled
with a mat of spicules similar to those forming the strands, and they
are arranged transversely and in general parallel to the adjoining
strands but may be directly transverse to the axis of the frond even
though the strands curve slightly (fig. 1, pl. 67) ; often the main
strands are obscured by the mat of fine spicules; usually the trans-
verse system of strands dominates to such a degree that the vertical
strands are not to be seen except by close observation with a magni-
fying glass of low power (fig. 1, pl. 66). The long strong spicules
appear to be buried in the wall or near the inner surface and are not
often seen; when exposed they are more or less irregularly placed
but in general parallel to the nearest margin of the frond; spicules
60 mm. in length have been measured where both ends were con-
cealed by a covering of shale; on one specimen these strong spicules
curve around subparallel to the rounded lower extremity of the
sponge. No traces of anchoring spicules have been observed. The
fine spicules forming the thick mat of the wall and the strands are
very fine, 0.026 mm. in diameter; some of the spicules in the strands
are a little coarser and have been traced 3 to 5 mm. in length before
disappearing in the strand or the adjoining mat of fine spicules.
The long vertical spicules average 0.15 to 0.20 mm. in diameter.

No. 6 MIDDLE CAMBRIAN SPONGIAE 281

Dimensions.—A slender frond 170 mm. in length varies from 38
to 45 mm. in width except where it narrows near the rounded ends;
one broken frond has a width of 80 mm. at the upper end and a
length of 190 mm. to where it is broken off by fracture of the shale;
a broad frond 140 mm. in length has a width of 85 mm.

Observations —Wapkia grandis is the best example of a Cam-
brian halichondrite sponge known to me; its form and structure are
finely preserved despite the rough treatment it had both before and
after being embedded in the muddy sediment. I do not know of any
closely related forms among either living or fossil species. The firm
outlines and strong appearance of the fronds indicate a strong
compact skeleton and sufficient spongin to give solidity and firmness
to the walls.

HAZELIA, new genus

Simple or branched, elongate cylindric or frondose thin-walled
sponges with a thin dense dermal layer in which fine spicules and
more or less of the skeletal spicules are embedded. The spicular
skeleton (reticulum) is formed of elongate vertical undulating
strands composed of exceedingly fine, elongate thread-like spicules ;
the strands bifurcate, and occasionally cross each other obliquely,
and irregular clusters of acerate spicules serve to bind the strands
together into a firm but loose skeleton; no transverse strands or
long spicules observed.

Genotype—Hazelia palmata Walcott.

Stratigraphic range—Middle Cambrian: Stephen formation;
Ogygopsis shale, on Mount Stephen; Burgess shale and superjacent
bedded limestone, which give a vertical range of about 450 feet
(ne7.25 m:)-

Geographic distribution.—At Burgess Pass fossil quarry, in Bur-
gess shale, on western slope of ridge connecting Wapta Peak and
Mount Field, and on west slope of Mount Field 1 mile (1.6 km.)
northeast of Burgess Pass above Field, also on northwest slope of
Mount Stephen above Field, British Columbia.

Observations.—The strands of the skeleton of Hazelia are similar
to those of Halichondrites elissa in being formed of very slender
threadlike spicules that presumably depended upon a fibrous con-

282 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

nective tissue to bind them together, but here the resemblance ends
as the strands of Hazelia are undulating, more or less inosculating
where they come in contact with each other and they also radiate
upward and outward from whatever may have been their basal point
of growth. .

Among living genera the arrangement of the dermal spicular layer
of Pachychalina* and Rhaphidophlus is suggestive of that of Hazelha,
but the main skeletal strands are more nearly like those of some of
the Hexactinellida, but they differ radically in being formed of diact
or monact spicules in Hazelia.

The species now referred to the genus are:

Hazelia conferta Walcott
Hazelia delicatula Walcott
Hazelia ? grandis Walcott
Hazeha mammillata Walcott
Hazelia nodulifera Walcott
Hazelia obscura Walcott
Hazelia palmata Walcott

HAZELIA PALMATA, new species -
Plate 69, figs. I, Ia-c; pl. 76, fig. 2

This species occurs as relatively thin fronds that grew in an up-
right position from a more or less narrow basal point of attachment ;
the fronds vary from a roughly circular outline to narrow elongate
stemlike growths; the prevailing outline is that of a small bush
expanding gradually to a broadly rounded summit.

Reticulum.—tThe skeleton is formed of several main lines of
irregular or undulating fibrous strands that branch upward in a close,
irregular dendroid manner, sometimes inosculating by sending out
thread-like spicules that merge in among those of the adjoining
strands; the spicules of the strands are very fine, often threadlike
and of variable length; they are best seen at the upper margin of
the frond where the strands project above the dermal layer or else on
slightly worn surfaces of the frond; as far as can be determined,
they are simple, diaxial spicules that were bound together by spongin
when the sponge was living and the strands were embedded in a
siliceous dermal membrane ; the strand spicules apparently have their
bases in the center of the strand and extend obliquely outward at
angles dependent on their length, some extended for 5 mm. or
more parallel to the axes of the strand. The dermal layer, when

*xRept. Voyage H. M. S. Challenger, Zool., Vol. 20, 1887, pl. 46, figs. 1, 4, 9.

No. 6 MIDDLE CAMBRIAN SPONGIAE 283

unworn, is filled with minute simple spicules crossing at any angle
and forming a matlike mesh; these spicules may or may not be inter-
laced with the spicules of the main strands; the strands vary from
0.5 mm. to 0.25 mm. and the spicules 0.08 mm. to 0.16 mm. in diame-
ter. There is no evidence of any system of transverse spicules such
as occur in Tupomia.

Dimensions.—The largest frond has a height of 604+ mm., with
a width of 40+ mm., and fragments indicate somewhat larger
fronds.

Observations—Most of the fronds have a fairly regular growth
of the skeletal strands, but some show irregular arrangemént as
though there had been a change in position of the frond and a new
direction given to the increased growth. The thickness of the frond
when living is unknown; it was probably thin as in the recent Myvilla
frondosa Ridley and Dendy.’

This is one of the most abundant forms of Hazelia, and is often
found matted down with fragments of crustaceans and algae in such
manner as to suggest that it was considerably decomposed when
embedded in the siliceous mud.

HAZELIA CONFERTA, new species
Plate 72, fig. 3

This is one of the cyathiform sponges that must have had a very
delicate skeletal structure with a thick dermal membrane and abun-
dant gelatinous tissue; the dermal membrane formed a strong
protective covering that in the fossil state consists of very thin
sheets pressed down on each other ; the gelatinous tissue was pressed
out from the edges of the specimen so as to form a line of irregular
blotches; the whole aspect of the fossil gives the impression that
the sponge was relatively soft and that it has been compressed until
it is reduced to several filmlike layers.

Reticulum.—Very fine straight simple spicules occur in the dermal
layer without any uniform arrangement. The skeletal framework
is indicated by several patches of a minute rectangular mesh form of

1Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, 1887, p. 144, pl. 26.
figs. I, Ia.

284 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

fine vertical strands crossed by still smaller transverse strands very
much as in the more clearly defined skeleton of Hagelia palmata.

Dimensions.—The type specimen has a length of 100 mm. with a
width as flattened of 50 mm. at the top; it terminates below in a
rounded end 8 mm. in width. A second and larger but more irregu-
lar specimen has a length of 135 mm. with a width of about 60 mm.,
40 mm. below the top; its lower end is rounded and there are traces
of simple short spicules extending out from it that may have served
to hold the rounded base in the mud.

Observations.—The type specimen indicates that the frond was
hollow as there is a layer of shale about 3 mm. thick between what
appears to have been the opposite walls of the sponge. The whole
appearance of the specimens is such that there is little to base a com-
parison with other species referred to the genus ; one broad specimen
of Hazelia delicatula (pl. 70, fig. Ie) has a general resemblance in
form and a very delicate skeletal structure, but it was a firm, well-
defined frond unlike that of H. conferta.

HAZELIA DELICATULA, new species
Plate 70, figs.I, Ia-g; pl. 90, figs. 2, 2a, 4

This species occurs in a variety of forms: round, oval (figs. 2, 4,
pl. 90), broad, elongate (fig. 1d, pl. 70), flattened stems (figs. Ie, Ig,
pl. 70) and branching (fig. 1, pl. 70).

Reticulum—the surface is slightly roughened by vertical, closely
undulating strands of very slender elongate spicules and similar but
small, short, transverse strands that cross the interspaces between
the vertical strands in an irregular manner, their ends being fastened
into the vertical strands, which gives a roughly irregular quadrangu-
lar mesh; on some portions of the surface the main strands have so
divided as to inosculate with the adjoining strands to form oval or
elongate oval spaces, the transverse strands not being present; both
features, quadrangular and oval species, may be present on the same
frond. Numerous delicate acerate spicules extend into the open
space of the mesh from the strands or they may lie across it without
any apparent relation to any other spicules or aggregated in minute
tufts ; these fine short spicules often form a spicular fringe about the
irregular spaces of the mesh (fig. Ic, pl. 70). The strand spicules

No. 6 MIDDLE CAMBRIAN SPONGIAE 285

vary from 0.08 to 0.16 mm. in diameter, and the strands are about
0.8 to I mm. across.

The dermal layer is a delicate membrane that is always present
but often so thin that spicules show through it as though it was a
tenuous film.

Dimensions —The largest single specimen has a length of 90 mm.
and a width of 25 mm. The one branching form has three strong
branches, and is illustrated by figure 1, plate 70; a number of irregu-
lar circular or oval fronds are above 15 mm. in diameter.

Observations —The dermal skeleton of this species recalls that of
the recent Pachychalina lobata Ridley and Rhaphidophlus filifer Rid-
ley and Dendy, and the skeletal framework of the latter is very sug-
gestive of the manner in which the spicular skeleton of Hazelia
may have been constructed.* In the fossil species we have only the
flattened fronds and can obtain very little conception of how the
skeleton was arranged transversely to the outer surface.

1, delicatula differs from H. palmata in details of the skeletal
structure and in the delicacy of the surface markings and skeletal
strands.

HAZELIA ? GRANDIS, new species
Plate 71, fig. 2

This species is represented by one weather-worn specimen that
retains portions of the dermal and skeletal layers replaced by
microscopic crystals of pyrite; the specimen indicates a thin-walled
elongate, cyathiform sponge with a skeleton built up of narrow
vertical spicular strands crossed transversely by rather delicate
strands, the two forming a minute quadrangular mesh; there is also
an indication of a dermal layer with fine, short, hairlike spicules; all
spicules are obscured by the coating of pyrite crystals.

Dimensions —The portion of the frond preserved has a length
of 125 mm. with a width of 42 mm. at the top and 5 mm. where
broken off at the lower end; the quadrangular spaces in the central
portion are about 1.5 mm. across as they are indicated on the matrix
where the sponge has flaked off.

1See Rept. Voyage of H. M. S. Challenger, Zool., Vol. 20, 1887, pl. 46,
figs. 4, 9.

286 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

This form is nearer to that of Hagelia obscura than to the other
species referred to the genus.

Formation and locality—Middle Cambrian: (14s) Ogygopsis
zone of the Stephen formation ; about 2,300 feet (701 m.) above the
Lower Cambrian and 3,540 feet (1,089 m.) below the Upper Cam-
brian in the Ogygopsis zone of the Stephen formation, at the great
“ fossil bed’ on the northwest slope of Mount Stephen, above Field
on the Canadian Pacific Railroad, British Columbia.

HAZELIA MAMMILLATA, new species
Plate 90, figs. 3, 3a

This species is represented by a fragment of the dermal surface
preserving four elevated mammez with a round osculum at the sum-
mit of each; between the elevations about the oscula numerous small
openings (pores?) occur that are surrounded by a meshwork of
fine, delicate acerate spicules; the meshwork is much like that of
Hazelia delicatula (pl. 70, fig. 1c).

Reticulum.—All that we know of the skeleton is the dermal mesh
of irregularly arranged, short, acerate spicules; these occur ahout
and between the small openings (pores) without any apparent regu-
larity of structure.

Dimensions.—The fragment of the dermal surface preserved has
a length of 15 mm. and a width of 9 mm.; the elevated ring about
the oscula has a diameter of about 4 mm. and each osculum I mm. ;
the pore-like openings between the oscula are about 0.25 mm. in
diameter. ;

Observations.—It is possible that this specimen belongs to a genus
distinct from Hazelia, but with the dermal skeleton of the same type
it appears reasonable to refer it to that genus pending the discovery
of further material. Among recent sponges the osculum-bearing
surface of Pachychalina ? punctata* is most suggestive of the sur-
face of this species.

+See Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, 1887, pl. 6, fig. 2b.

No. 6 MIDDLE CAMBRIAN SPONGIAE 287

HAZELIA NODULIFERA, new species
Plate 71, figs. 3, 3a-b

In this species the skeletal strands are closely undulated and they
bear numerous nodes formed of tufts of fine short acerate spicules,
the bases of which are more or less included with the main spicules
of the strand; a dense dermal membrane, in whose strands tufts of
spicules and fine dermal spicules are embedded, covers the surface
and it is only on worn specimens that the skeletal structure and
spicules are to be seen.

Dimensions.—A large broken frond covers a space 80 by 80 mm.,
and it was probably 120 mm. or more in height; a small frond at-
tached to a brachiopod (Nisusia alberta, pl. 71, fig. 3) is 20 mm. in
height and 10 mm. in width. The nodes vary in size on different
fronds from 0.25 mm. to I mm., and they may be round or elongate
in outline.

Observations.—This form is so well marked that I have separated
it as a species although it might possibly be considered as a nodose
variety of H. palmata.

HAZELIA OBSCURA, new species
Plate 71, figs. I, Ia

Of this species there are seven simple elongate specimens, none of
which show indications of branching. The gradual enlargement in
width and gentle curvature are present in five specimens, and all have
a dense dermal layer that nearly obscures the skeletal structure ;
the few traces of the latter indicate it closely resembled that of
Hazelia delicatula, but the spicules and the meshes of the skeleton
are much smaller and the dermal layer is more dense. Transverse
undulations suggest that the fronds were hollow and thin-walled,
but there is no conclusive evidence of it, and all the specimens now
appear to the eye to be simply smooth, flat membranous stems lying
on the dark shale.

Dimensions.—The longest specimen has a length of 100 mm. and
a width of 15 mm. at the upper end and 4 mm. where it is broken off
at the base ; another specimen has a width of 22 mm. near the upper
end and 10 mm. where it is broken off 75 mm. below; one fragment
has a uniform width of 17 mm. for a distance of 45 mm,

288 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Observations.—All the specimens appear to have grown in an
upright position and to have been broken off from their base before
being drifted along to their final resting place where they were
found widely distributed. They range through about 10 feet
(3.05 m.) in thickness of the shale.

Formation and locality—Middle Cambrian: (35k.) Burgess
shale member of the Stephen formation; on the west slope of the
ridge between Mount Field and Wapta Peak, 1 mile (1.6 km.)
northeast of Burgess Pass, above Field on the Canadian Pacific Rail-
way, British Columbia.

CORRALIA, new genus

General form in the fossil state an erect, gradually expanding,
undulating flattened cone with apex at the base. Spicular skeleton
formed of closely arranged, strong vertical strands of simple elon-
gate fine spicules. Dermal layer thin, dense and penetrated by slender
spicules more or less connected with the vertical strands.

Genotype—Corralia undulata Walcott.

Stratigraphic range-—Lower 10 feet (3.05 m.) of the Burgess
shale.

Geographic distribution.—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Bur-
gess Pass, above Field, British Columbia.

Observations —The species of this genus might be included under
Hazelia except for the closely arranged vertical strands, strong
undulation of growth, and probable tubular form. The spicules are
obscured by the dermal layer, but can be seen fairly well with a
strong lens. The type species is the only one thus far referred to
the genus.

CORRALIA UNDULATA, new species
Plate 72, figs. 2, 2a

The specimens of this species occur as flattened elongate undu-
lating slender cones with the sides gradually expanding from the
base upward.

Reticulum.—tThe skeletal strands are about 1 mm. across near the
upper end where the specimen is 20 mm. in width; they are separated
by very narrow spaces or else touch each other ; some of the strands
look as though they were made of a bundle of smaller parallel
strands; spicules obscure owing to covering by dermal layer, but
where visible they are delicate, threadlike and appear to be parallel
with the strand; by reflected light a series of minute transverse

No. 6 MIDDLE CAMBRIAN SPONGIAE 289

strands may be seen crossing some of the spaces between the ver-
tical strands in such manner as to divide the space into minute
rectangles. The dermal layer has been so largely replaced by
microscopic crystals of pyrite (FeS,) that its spicules are rarely seen,
a few minute monacts are visible towards the lower end of the
specimen represented by figure 2.

Dimensions—The largest specimen has a length of 75 mm. to
where it is broken off above its base; as flattened its width is 25 mm.
near the upper end and 15 mm. wide 40 mm. below.

Observations —This species appears to have characters of both
Tuponia and Hazelia, but it is hardly near enough to be included in
either genus ; with more and better preserved specimens it may prove
to belong to one or the other, probably Hazelia, but with present
information it is considered distinct and taken as the type of a genus.

At one place on the matrix there is a suggestion of the spicular
structure of Vausxia, but whether the narrow vertical lines are casts
of the spaces between the slightly convex ribs or ridges above or are
true spicules cemented together as in Vawsxia is not readily deter-
minable.

SENTINELIA, new genus

Of this form there are only two species, represented by fragments
that appear to have been broken from a sponge somewhat similar in
form to the Hexactinellid, Euryplegma auriculare Schulze.” This
superficial resemblance is unfortunately all there is for comparison
with recent sponges as the skeletal structure of the fossil form is
unknown, except that there are indications of simple monact spicules
of varying length, some of which are gathered in radiating tufts
which leads to the provisional reference of the genus to the Monacti-
nellida. Both specimens are fragments of thin flat fronds with numer-
ous round or oval flat tubercles scattered over the surface in which
openings may have occurred.

Genotype.—Sentinelia draco Walcott.

Stratigraphic range—S. draco occurs in the Stephen formation
about 1,000 feet (305 m.) above the base of the Middle Cambrian

*Rept. Voyage H. M. S. Challenger, Zool., Vol. 21, 1887, p. 176, pl. CII.

290 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

in the Castle Mountain section of Alberta. A form doubtfully iden-
tified with it is from the Wheeler formation at about 1,580 feet
(481.9 m.) above the base of the Middle Cambrian in Utah.

Geographic distribution—S. draco is from Mount Stephen in
British Columbia, Canada, and the Utah specimen from the House
Range of central western Utah, United States.

Observations.—The chief value of this genus is in the indication
that there was a group of sponges living in Middle Cambrian time of
which we have only two fragmentary specimens.

SENTINELIA DRACO, new species
Plate 72, figs. I, Ia

This species is represented by fragments of a frond having numer-
ous round or oval, almost flat tubercles ; some of the smaller tubercles
have small openings in them, and this may have been the case with
all the larger tubercles now open by erosion of the filmlike outer layer
from off the top; how much of this was formed by original openings
it is impossible to determine.

_ -Reticulum.—Only faint traces of any skeletal structure are pre-

served ; these indicate an irregular, minute reticulate mesh formed
of slender straight spicules. The dermal layer is thin and the pres-
ence in it of minute simple straight spicules is indicated by raised
lines on the surface.

The type fragment representing this sponge covers most of a space
50 by 60 mm. in size and shows no natural boundaries.

Observations—The specimen referred to above and taken as the
type of the species is from British Columbia; the second specimen,
which is represented by figure 1a, is from Utah, and both occur in
Middle Cambrian rocks. The Utah specimen is tentatively included
under the species on account of its resemblance in form, as it is
little more than a cast of the original fragment ; it has one side with
natural outline and it retains a slight convexity.

Formation and locality—Middle Cambrian: (58 m) Stephen
formation. About 1,000 feet (305 m.) above the top of the Lower
Cambrian in bluish-black and gray limestone (138 feet =42.09 m.)
of the Stephen formation, Castle Mountain section ; northeast slope
of Castle Mountain, facing amphitheater, north of Canadian Pacific
Railway, Alberta, Canada.

(3t) Wheeler formation: About 1,700 feet (518.2 m.) above the
Lower Cambrian and 2,700 feet (823 m.) below the Upper Cam-
brian in the shaly limestones and calcareous shales of the Wheeler

No. 6 MIDDLE CAMBRIAN SPONGIAE 291

formation, in the eastern part of Wheeler Amphitheater, east of
Antelope Springs, House Range, Millard County, Utah, U.S. A.

Family SUBERITIDAE
CHOIA, new genus

- Sponge, free, with a thin circular central disk, from the center
of which spicules radiate to and beyond the margin of the disk; the
central body or disk appears to have had one side slightly concave
(upper) and the opposite rising to a central node or point (lower
side).

Reticulum.—The central disk is formed on its lower side of a
dense mass of fine spicules that radiate from a central point out to
the not very sharply defined margin beyond which many of the small
spicules extend as a fine fringe, and the long rodlike spicules which
originate near or at the center continue on far beyond the disk ; the
bases of the long, relatively large spicules (probably monacts) are
buried in a mass of spicules or lie outside of them on the upper
side of the disk; the upper side of the disk has a more or less con-
fused mass of fine spicules at the center, from which many of the
larger, rod-like spicules radiate to and beyond the margin of the
disk. There is no recognizable dermal layer, although in Chova
ridleyi there is a dense layer on the lower side of the disk which I
think is the flattened lower convex side, formed of matted layers of
the fine radiating spicules.

Dimensions.—Most of the species are small with disks 10 to
15 mm. in diameter, but Choia hindet had a disk 60 mm. or more in
diameter and that of C. utahensis was 40 mm. across.

Genotype.—Chota carteri Walcott.

Stratigraphic range—Choia cartert and C. ridleyi occur in the
Middle Cambrian Burgess shale 1,920 feet (585.6 m.) above the
Lower Cambrian; C. utahensis is from the shaly portion of the Mar-
jum formation 2,135 feet (656 m.) above the Lower Cambrian;
C. hindei is from the Metis shale of probable Middle Cambrian age
but its relations to the Lower Cambrian are unknown.

Geographic distribution —C. carteri and C. ridleyi are from above
Burgess Pass, British Columbia, Canada, C. utahensis from western
central Utah, and C. hindei from the shore of the St. Lawrence
River at Little Metis, below Quebec, Canada.

The genus is tentatively determined from the Middle Cambrian
Menevian formation of St. Davids, Wales, by the species Choia
fabella (Hicks).

292 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The species now referred to Choia are:

Choia cartert Walcott
Choia flabella (Hicks)
Choia hindei (Dawson)
Choia ridleyi Walcott
Chota utahensis Walcott

Observations —This most interesting genus may be compared
with the living sponge Trichostemma sarsii Ridley and Dendy* a
deep-water species from off the Azores and in the Australian seas.
It has the same type of skeletal structure and general form. It
is very easy to imagine specimens of this living sponge flattened by
pressure assuming the appearance of Chota carter.

Dr. George J. Hinde described a fossil sponge from the Utica
shale of the Ordovician system which he named Stephanella sancta.’
This sponge occurs in circular films or patches on the shale from
8 to 10 mm. in length and of an average thickness of 0.035 mm.
Dr. Hinde stated, “It may be taken for granted that each of the
numerous circular patches in this rock indicates the basal portion
of a distinct sponge; but it is hardly likely that it represents the
entire skeleton of the organism and it is insufficient to determine
conclusively the nature of the sponge.” He calls attention to a sug-
gestion of Sir J. W. Dawson that they may be the root spicules of
Hexactinellid sponges.

It is possible but not probable that the Middle Cambrian species
described in this paper are congeneric with the Ordovician Utica
shale species described by Dr. Hinde, but with our limited informa-
tion in regard to the latter I prefer to place the Cambrian species in
a genus which I consider was a free sponge with a central disk that
in no way served as a part of a larger skeleton.

CHOIA CARTERI, new species
Plate 72, fig..45-pl..73, aes.teiG-be pl. 75 shone
In the fossil state this species occurs as a flat circular disk with a
fringe of fine straight spicules and a corona of long, slender strong
spicules. Some of the specimens have a slight elevation or node at
the center of the side that is formed of a dense mass of fine radiating
spicules and on the opposite side which is flat or slightly depressed
there are many straight irregularly arranged spicules of varying

* Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, p. 218, pl. XLIII, figs. 1-4,
? Geol. Mag. London, N. Ser., Dec. III, Vol. VIII, 1801, pp. 22-24. Text fig.
unnumbered.

No. 6 MIDDLE CAMBRIAN SPONGIAE 293

length, from among which long straight spicules radiate to and far
beyond the margin of the disk. As may now be determined the disk
was slightly concave or flat above and more or less convex on the
lower or opposite side. To what extent the long spicules radiated
from more than the one horizontal plane they now occupy is un-
known, but they probably extended outward in a broad belt so as to
keep the sponge from sinking into the muddy bottom.

Spiculum.—There are no indications of a skeletal framework
other than a mass of detached spicules that may have been held
together by spongin fibers or by the interlacing of the spicules of the
disk ; the finer spicules are about 0.16 mm. in diameter and of unde-
termined length, owing to the manner in which they are matted
down together to form thick, thatchlike layers on the under side
from the center to the outer margin of the disk, and many of them
extend from I to 3 mm. beyond the margin as a fine fringe; frag-
ments 2 to 3 mm. in length may be measured; the long, rodlike
spicules may be monacts but some of them appear to taper to a
slender point at both ends; they vary from 0.32 to 0.64 mm. near disk
and 0.4 to 0.8 mm. in diameter about 5 mm. from disk ; some of those
on the type specimen have a length of 18 mm., and on another speci-
men with a disk 10 mm. across a few are 25 mm. in length; several
of these long spicules have spiral lines on the outside, and many are
so broken in by compression as to indicate the presence of a central
canal.

Dimensions.—The broadly oval disk of the type specimen, which
is very much compressed and slightly distorted, is 12 by 15 mm. in
diameter with long spicules on the average extending 10 mm. beyond
the margin ; on another specimen with a nearly circular disk the long
spicules project about 15 mm. beyond the disk and a few 20 mm.; to
these lengths we must add 4 to 5 mm. to obtain the entire length;
the largest specimen has an oval disk 15 by 25 mm. in diameter,
resulting probably from distortion of a circular disk.

Observations —The confused mass of broken or short spicules is
illustrated by figure 2, plate 75, the thatchlike mass of fine spicules
by figure 1b, plate 73, and a fragment of the convex side of a disk
by figure 1a, plate 73. C. ridleyi occurs in the Burgess shale but not
in the same layer as C. carteri; it differs in its smaller average size
and the long spicules are proportionally larger; C. carteri has only
a general resemblance to C. hindei and C. utahensis.

C. cartert is represented in the collection by 10 specimens.

The specific name is given as a recognition of the work of
Mr. H. J. Carter on the structure of the Hexactinellidae.

294 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Formation and locality—Muddle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of
Burgess Pass, above Field; (14s) Ogygopsis zone of the Stephen
formation ; about 2,300 feet (701 m.) above the Lower Cambrian and
3,540 feet (1,089 m.) below the Upper Cambrian in the Ogygopsis
zone of the Stephen formation, at the great “ fossil bed”’ on the
northwest slope of Mount Stephen, above Field, on the Canadian
Pacific Railway, British Columbia.

CHOIA RIDLEYI, new species
Plate 73, figs. 2, 2a; pl. 74, figs. I, Ia

The general form and appearance of this species is the same as
that of C. carteri except that it is smaller and more delicate and the
long spicules are relatively stronger.

Reticulum.—tThe spicular structure is essentially the same as that
of C. carterit except that the large spicules are much more promi-
nent on the upper side and the fine spicules of the under side
are finer and the thatchlike structure more dense. The smaller
spicules average about 0.08 to 0.12 mm. in diameter and from 2 to
3 mm. in length; the large rodlike spicules average from 0.4 to 0.48
to 0.56 mm. in diameter a short distance beyond the disk, and some
of them are 10 mm. in length from a disk 4 mm. across as flattened in
the shale.

Dimensions.—The largest disks average 6 mm. in diameter, and
the greater number less than 5 mm.; the longest spicules extend
8 mm. beyond the margin of the disk.

Observations —This little species was found in considerable
numbers on a limited surface of shale; one fragment 40 by 70 mm.
has over 40 individual sponges flattened upon it. The differences
between this and C. carteri are mentioned under the description of
that species.

The specific name is in recognition of the work of Mr. Stuart O.
Ridley, associate author with Mr. Arthur Dendy of the report on
the Monaxonida (Monactinellida) of the Challenger expedition.

No. 6 MIDDLE CAMBRIAN SPONGIAE 295

CHOIA UTAHENSIS, new species
Plate 75, fig. I

Of this species there is but one weathered specimen lying on the
surface of a piece of shaly limestone. Most of the spicular struc- >
ture has been eroded, but sufficient remains to outline the disk and
the long radiating spicules.

Reticulum—The disk was formed of a mass of fine elongate
spicules radiating from the center to the edge of the disk, also long
slender spicules interbedded in or resting on the fine spicules from the
center outward and extending far beyond the margin; the spicules
have all been replaced by calcite and a few retain their size and form;
a small, fine spicule is about 0.1 mm. in diameter, and a long large one
at 10 mm. from the margin is 0.5 mm. in diameter and its length
38 mm.

Dimensions.—Disk 38 mm. in diameter as flattened; the largest
spicules extend out about 18 to 22 mm. beyond the margin.

Observations.—This large species is readily identified with the
genus ; its size seems to separate it from C. cartert and C. ridleyi,
and its structure as far as known from C. hindet, and it probably
occurs at a somewhat lower horizon than the latter species.

Formation and locality—Middle Cambrian: (3y) About 2,150
feet (655.3 m.) above the Lower Cambrian and 2,250 feet (685.8 m.)
below the Upper Cambrian, in the shaly limestones forming 1d of the
Marjum limestone,’ 2.5 miles (4 km.) east of Antelope Springs, in
ridge east of Wheeler Amphitheater, House Range,’ Millard County,
Utah.

CHOIA HINDEI (Dawson)
Plate 76, figs. I, Ia
Stephanella hindii Dawson, 1896, Trans. Royal Soc. Canada, 2d ser., Vol. 2,
Sec. IV, p. 117, fig. 28.

This is the largest species of the genus and fortunately there is
sufficient of it preserved to indicate its size and character.

Reticulum.—tThe one large disk has a distinct round elevation at
at the center about 15 mm. in diameter from the center of which a
dense mass of slender spicules radiate towards the outer margin;
these fine spicules are 10 mm. or more in length, and average
0.16 mm. in diameter ; this lower side of the disk also has a mesh of

* Walcott, Smithsonian Misc. Coll., Vol. 53, Cambrian Geol. and Pal., No. 5,
1908, p. I8o.
* Idem, pl. 13.

206 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

criscrossing short fine spicules over the central portions of the thick
thatch of radiating spicules; a series of long, slender spicules are
embedded in and radiate outward from the central part of the disk
to the margin and from 40 to 50 mm. beyond; they are slender,
0.3 to 0.4 mm. in diameter, when their great length is considered.

Dimensions.—The one fairly well outlined disk is 60 mm. in
diameter, and a fragment indicates a disk 80 mm, or more across
with long spicules extending 40 to 50 mm. out beyond the disk.

Observations —A fragment of a large disk has many of the deli-
cate fine spicules radiating outward from the mass of the disk
spicules, and there are also many broken or short spicules lying in
and on the surface of the disk; nearly all of the long spicules pene-
trate into the mass of fine spicules on all of the specimens which
indicates that none of them show the upper surface of the disk,
which is usually in C. carteri and C. ridleyi formed largely of the
long, stouter spicules.

This species is represented in the U. S. National Museum col-
lections by about three-fourths of a large disk and large fragments
of the marginal spicules of two other specimens. I did not realize,
when collecting at Little Metis, that they represented a rare form,
or I would have searched for all the fragments despite the incoming
tide ; it was a case of prying the shale loose, grabbing all possible,
and running back from the onrushing water.

The specimens described by Sir W. J. Dawson are evidently the
same in character as those I collected, but they are illustrated from a
drawing made prior to his finding the best specimens. This drawing
was published in 1889 °* as a spinose sponge.

Formation and locality— Middle ? Cambrian: (339s) Little Metis
black argillaceous shale, Little Metis, Province of Quebec, Canada.

HAMPTONIA, new genus

Globose, bladderlike shaped forms with thin loose walls. The
spicules of the skeletal framework radiate in a more or less irregular
manner; spiculae monactinal or diactinal. Traces of spongin
present.

Genotype—Hamptonia bowerbanki Walcott.

Stratigraphic range-——Lower 10 feet (3.05 m.) of the Burgess
shale.

1 Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 1880, p. 53, fig. 24.

No. 6 MIDDLE CAMBRIAN SPONGIAE 297

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Burgess
Pass, above Field, British Columbia.

Observations —Among living forms the rotund forms of Tricho-
stemma* might under great compression give a flat thin structure
somewhat similar to that of H. bowerbanki but Hamptonia indicates
a looseness of skeletal structure and irregularity of form not known
in Trichostemma. By taking a confused mass of the diactinal
spicules of Bathydorus uncipe F. E. Schulze and pressing them down
between glass plates a mass of irregularly scattered slender spicules
was obtained that resemble the scattered spicules on the surface of
some portions of the body of Hamptonia bowerbanki.

HAMPTONIA BOWERBANKI, new species
Plate Zou ne. se ple77s fe tpl. 75) es. 1, a,

The specimens representing this species are compressed until there
is little more than a film of varying thickness on the shale; the sur-
face has a brownish color and is more or less coated with microscopic
crystals of pyrite.

Reticulum.—tin the smaller specimens long, very slender spicules
radiate in a matted mass from a spot that was probably the base
of a more or less globular form of sponge; these spicules vary from
0.16 to 0.4 mm. in diameter and fragments 10 mm. in length are scat-
tered about irregularly on the outer surface ; in places on the margin
the spicules extend a distance of 3 to 5 mm., forming a delicate
fringe; on the surface of large specimens the spicules may radiate
from two or more centers or from one or more lines following the
longer axis of the sponge ; in all specimens there is a space of varying
width near the margin where the main body of the spicules extend
outward at right angles to the margin.

Dimensions.—The largest specimen outlining the body of the
sponge has a total length of 210 mm. and greatest width of 150 mm. ;
it probably represented an elongate globose mass with a major axis
of 140 mm. and a minor axis of 100 mm,

Observations—This is an unsatisfactory species to deal with on
account of its condition and the absence of well-defined characters
other than the irregularly radiating spicules and the general impres-
sion made that we have the remains of what was once a rather soft
globular sponge.

*Rept. Voyage H. M. S. Challenger, Zool., Vol. 20, 1887, pl. XLIII.

208 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Hamptonia differs from Choia in its looseness of structure and
absence of strong radiating spicules; it probably grew in the same
form and manner as Choia to the extent of not being attached to a
fixed object. All of the specimens indicate that a thin-walled soft
globular body was flattened in the shale, the spicular skeleton mat-
ting down in several thin parchment-like layers or forming only a
thin film.

The presence in all specimens of a distinctly outlined form and
the retention of the mass of spicules in a more or less regular ar-
rangement indicates that there was sufficient spongin to serve as a
base for holding both the general form and the loose spicular frame-
work in position.

PIRANIA, new genus

Tubular, simple stemmed or branched; growing from an obtusely
pointed base ; not known to have been attached.

The skeletal structure and comparisons are given in the description
of the one known species.

Genotype-—Pirania muricata Walcott.

Stratigraphic range——Middle Cambrian: Stephen formation;
Ogygopsis shale, on Mount Stephen; Burgess shale and superjacent
thin-bedded limestone, which give a vertical range of about 450 feet
(137.25 m.).

Geographic distribution—At Burgess Pass fossil quarry, in Bur-
gess shale, on western slope of ridge connecting Wapta Peak and
Mount Field, and.on west slope of Mount Field 1 mile (1.6 km.)
northeast of Burgess Pass above Field, also on northwest slope of
Mount Stephen above Field, British Columbia, Canada.

Observations—The details of form and structure are given under
the description of the type species.

PIRANIA MURICATA, new species
Plate 7O figs. 1a-e
Numerous specimens more or less crushed and flattened in the

shale prove that the body of the sponge was in the form of a rather
small, round, hollow stem, with one offshoot, as far as known, which

No. 6 MIDDLE CAMBRIAN SPONGIAE 299

branched from the main stem at an acute angle. The body is formed
of an outer plated wall, an interior wall (as yet of unknown struc-
ture), and an intervening space filled up with spicules and spongin
that in the fossil condition is a mass of microscopic pyrite crystals
which have replaced the organic matter, which is a common form of
replacement among the fossils of the Burgess shale. The top of the
tube is closed by a transverse layer of about the same depth as the
thickness of the side walls.

Reticulum.—tThe outer surface of the sponge wall is covered with
small hexagonal, slightly convex plates arranged in diagonal lines,

O
i

Pirania muricata Walcott

Fic. 4—Diagrammatic outline of section of the stem showing interior outer
walls, large spicules and fine spicules at the base.

Fic. 4a.—Summit and side outline of plate spicule.
each plate is at the outer end of a stout spicule rounded off at the
inner end ; at the base of the body there is a cluster of minute slender
spicules that radiate and cross each other in all directions; from
the base to the summit long, more or less curved spicules with an
expanded base (Tylostyli) and central canal radiate obliquely out-
ward from the body.

The plates on a full-grown specimen are 0.4 to 0.6 mm. in diameter
and the spicule (monact) attached from 0.5 to 0.6 mm. in length,
and the large spicules average 0.6 mm. in diameter near the body of
the sponge and extend out from it 6 to 8 mm.

300 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Dimensions.—The body of an unbranched specimen has a length
of 18 mm. exclusive of the long spicules, and a width flattened in the
shale of 5 mm. The main stem of a specimen with one branch 20
mim. long is 25 mm. in length and 4 mm. wide at the top.

Observations——I have examined 60 or more specimens of this
species for spicules with three or more rays (triacts, tetracts, pen-
tacts and hexacts), but without finding anything suggestive of
their presence. The plate headed spicules of the outer body wall
are very delicate and rarely preserved so as to show more than the
outer portion of the plate, but on the broken-down edges of the wall
in two specimens their inner extension is clearly shown; this has been
flattened, but it evidently had a rounded blunt end and there are no
traces of transverse rays.

None of the specimens show clearly how the large spicules pass
through the outer wall; they originate in the interior, and their
oblique course may be traced out to the margin of the body as the
wall has been moulded over the spicules by pressure in the process’
of fossilization ; one split-open specimen that is 3 mm. in diameter
shows a hollow interior I mm. in diameter with walls I mm. thick;
the bases of the oblique spicules enter the side walls but do not pene-
trate the interior. When the spicules are crowded together as in
figures Id, te, they suggest the presence of another species or variety,
but I think this is owing to accidents of preservation and not to an
original difference in form.

Pirania has been found in nearly all of the layers of shale at the
Burgess Pass quarry, and fifty or more specimens were collected
during the five seasons’ work.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass; (61]) Stephen formation ; yellow weathering band
of calcareo-argillaceous shale, west slope of Mount Field, near Bur-
gess Pass ridge about 3,000 feet (915 m.) above Field; also (14s)
Ogygopsis zone of the Stephen formation; about 2,300 feet
(701 m.) above the Lower Cambrian and 3,450 feet (1,089 m.)
below the Upper Cambrian in the Ogygopsis zone of the Stephen
formation, at the great “ fossil bed ” on the northwest slope of Mount
Stephen, above Field, on Canadian Pacific Railway, British Columbia.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 301

Order HEXACTINELLIDA O. Schmidt

(Triaxonia F. E. Schulze)

“Siliceous sponges with six-rayed skeletal elements, the rays being normally
disposed in three axes intersecting at right angles, and containing axial canals;
elements either detached or fused together so as to form a lattice-like mesh.
Dermal and flesh spicules exceedingly variable in form, but invariably six-
rayed.”

Sub-Order LYSSACINA Zittel

Skeletal elements either entirely detached, or only partially and
in an irregular fashion cemented together. Root-tuft often present.

Family PROTOSPONGIDAE Hinde

Thin-walled, sack-, tube-like or spherical sponges, with walls com-
posed of a single layer of cruciform tetraxial spicules (stauractins),
arranged so as to form quadrate and subquadrate meshes. Ele-
ments non-fasciculate. The reticulation formed by the larger ele-
ments is divided into secondary squares by smaller spicules, so that
the mesh-work is constituted of several series of squares.’

Genus PROTOSPONGIA Salter *
Dr. George J. Hinde described this genus as follows: *

Sponges probably cup- or vase-shaped, with walls consisting apparently of a
single layer of spicular mesh. This is composed of cruciform spicules of
varying dimensions; the larger are arranged so as to form a regular quadrate
framework, which is divided into secondary squares by smaller spicules, and
these are again subdivided in a similar manner, so that, when complete, there
are four or five series of squares. The spicular rays appear to have been
organically cemented together at their points of junction with each other, and
there are traces of a delicate membrane in the interstitial areas between the
rays, which may have united the entire meshwork together.

To the above there may be added as the result of the discovery of
finely preserved Hexactinellid sponges by Dr. B. J. Harrington at
Little Metis, Province of Quebec, and described by Sir J. W. Dawson
assisted by Dr. Hinde, the following notes on the genus by
Dr. Hinde.*

There are some differences of opinion as to the character of the spicular
mesh-work and the systematic position of Protospongia, and fresh light on

*The above definitions are those given in Eastman’s American edition of
Zittel, Text-book of Pal., 1913, pp. 59, 60.

* Quart. Jour. Geol. Soc., Vol. XX, 1864, p. 238.

* British Fossil Sponges, Pt. II, 1888, p. 105.

* Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 1880, pp. 30-44.

302 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the points contested is afforded by these Quebec specimens. It has been
doubted whether the body-wall of the sponge merely consisted of a single
layer of spicules, or whether this layer corresponded to the dermal layer in
other sponges of this group, and, as in these, was supplemented by an inner
spicular skeleton. The evidence of the Quebec specimens favors the view that
the body-wall of the sponge consisted only of a single layer of spicules.
Various opinions have likewise been held as to whether the body-spicules were
free, and merely held in their natural positions by the soft animal tissues, or
whether they were cemented together by silica at the points where their rays
are in contact. Prof. Sollas, in an able paper on the structure and affinities of
the genus (Quart. Journ. Geol. Soc., Vol. XXX, p. 366), asserts “that they are
separate, and not united either by envelopment in a common coating or, by
ankylosis”; whereas it would seem that a certain degree of organic union
must have existed to have allowed even the partial preservation of the mesh-
work of the body-wall in the fossil state, and I have regarded the delicate film
of pyrites, which extends over the mesh-work in many specimens, as indicating
a connected spicular membrane which served to hold the larger spicules in
position. From the study of the Quebec specimens I still think a certain degree
of organic attachment existed where the spicular rays were in contact, but I
am quite prepared to admit that it was not of the same complete character as
in typical Dictyonine hexactinellids. Prof. F. E. Schulze has clearly shown
that a certain degree of irregular coalescence takes place in the body-spicules
of undoubted Lyssakine sponges, and now that we know that Protospongia was
furnished, like most of the sponges of this group, with anchoring spicules,
there is good reason to regard this and the allied Palaeozoic genera as belong-
ing rather to the Lyssakine than to Dictyonine hexactinellids. This is the
position assigned to them by Carter and Sollas.

From the study of collections obtained after the above was written
Dawson added to the description the species P. tetranema, P. monon-
ema, P. polynema, and P. delicatula.. From these the following
description of the genus is derived.

Sponge body globular, rounded or broadly oval with an osculum
at the summit and slender anchoring spicules.

Reticulum.—Wall of the sponge formed of a single layer of cruci-
form spicules of various dimensions so arranged as to form a frame-
work with quadrate or oblong interspaces. The rays of the large
spicules form the boundaries of the larger spaces and the smaller
spicules the secondary and tertiary interspaces. The rays of the indi-
vidual spicules appear to have been united by sarcode or held in a
fine spicular film and not cemented together by a siliceous cement.
The osculum has short spines about it and there may be a great
development of protective dermal spines. The rays of the large body
spicules taper gradually from the central body to their pointed
extremities ; the rays of the smaller spicules and the slender dermal

* Trans. Royal Soc. Canada, 2d ser., Vol. 2, Sec. IV, 1806, pp. 101-106.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 303

and protective spicules appear to be nearly cylindrical. The anchor-
ing rods or spicules vary from the single rod of P. mononema to the
four rods of P. tetranema. The latter are slender, filiform, cylin-
drical rods, pointed at both ends, with their proximal ends inserted
apparently in the basal part of the body of the sponge; the anchoring
rod of P. mononema is described as having from two to four short
spreading branches at the base or a single elongated anchor-shaped
spicule with fine rays.

f—4
ELISA
Sr

2D:

BAS

“&
X

Fic. 5.—Protospongia mono- Fic. 6.—Protospongia mononema. Cruciform
nema. Restored. and protective spicules, X 5.

The presence of a dermal membrane is indicated in many speci-
mens by a rusty brown covering of minute pyrite crystals.

The studies of Dawson and Hinde indicate that Protospongia is
the simplest known form of the Hexactinellida and its occurrence
in the Lower Cambrian proves it to be one of the earliest sponges yet
known from Cambrian strata. The spicules from the Lower Cam-
brian * are apparently identical with those from the Middle Cambrian
of Wales.

Dawson gives diagrammatic figures of two species of the genus,
one of which is reproduced here for comparison with the Burgess
shale species and as illustrating the genus.’

* Tenth Annual Rept. U. S. Geol. Survey, 1890, p. 597, pl. XLIX, fig. 2.
* Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 188, p. 40, figs. 5 and 6.

304 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The spicules referred to Protospongia from the Middle Cambrian
of eastern Asia indicate two species, one of which I gave a definite
_name, P. chloris,’ and which is quite distinct from P. fenestrata, but
may be compared with the stronger spicules of P. hicksi. The
spicules of the second species, Protospongia sp. undt.’ are similar to
the more slender spicules of those from western America that I have
tentatively referred to Protospongia Iicksi Hinde. The Chinese
specimens occur in limestone and have round smooth rays; the figure
illustrating the spicule (fig. 4, pl. 1 of Chinese report) incorrectly
represents a median depression on the ray.

The species from the Little Metis shales now referred to
Protospongia are:

Protospongia delicatula Dawson
Protospongia mononema Dawson

Protospongia polynema Dawson
Protospongia tetranema Dawson

The species now recognized from undoubted Cambrian strata are:

Protospongia fenestrata Salter, Lower and Middle Cambrian
Protospongia hicksi Hinde, Middle Cambrian

Protospongia erixo Walcott, Middle Cambrian

Protospongia chloris Walcott, Middle Cambrian

PROTOSPONGIA FENESTRATA Salter
Plate 80, figs. 1, ta-b, 2

Protospongia fenestrata SALTER, 1864, Quart. Jour. Geol. Soc., Vol. XX,
1864, p. 238, pl. XIII, figs. r2a-b. (Original description and illustra-
tions. )

Hinde in his monograph of British Fossil Sponges, 1888, p. 106,
gives the Synonymy of this species up to that date and describes what
he knew of the species as follows:

The fragments of the wall of this species which have been preserved are
insufficient to indicate the probable form of the Sponge. The cruciform
spicules forming the skeletal mesh are of a delicate character, the rays are
circular in section and nearly of an even thickness throughout their length.
It is probable that the spicules were originally rectangular, but in the type
specimen the rays are now oblique, owing to the distortion produced by the
compression of the rock matrix. There are five different series of squares in
the Sponge-wall, the rays bounding the largest squares are 8 mm. in length
by 0.2 mm. in thickness, whilst the rays forming the secondary and smaller
squares are 4 mm., 2, I, and 0.5 mm. in length, respectively. The junction of

1Research in China, Carnegie Institution of Washington, Vol. 3, 1913,
Pubs NowsANpe5O eplnlmics ae aca:
* Idem, p. 60, pl. 1, fig. 4.

No. 6 MIDDLE CAMBRIAN SPONGIAE 305

the rays with each other is, in no case, distinctly shown; they can be traced
nearly to the point of contact, and do not apparently overlap the squares in
which they are situated:

The typical example of this species, now in the British Museum, exhibits a
fragment of the Sponge-wall on the surface of a slab of hard, black shale.
The original silica of the spicules has been replaced by iron-pyrites, and a
delicate film of this mineral extends over the surface of the Sponge, and is
probably a replacement of a siliceous dermal membrane, which served in part
to hold the spicular mesh together. Not only is the spicular framework
distorted, but in all the specimens I have seen it is partially broken up and
many of the spicules absent or displaced.

I collected a few fragments of the wall at St. Davids in 1888 and
among them have found a group of rectangular spicules (fig. Ia,
pl. 80) with two very long and two shorter rays. The rays are round
and ornamented with a very fine irregular fretwork which is probably
caused by a slight erosion of the surface; on another specimen there
are a number of long, simple delicate anchoring spicules (pl. 80,
He, -T):

Dr. Hinde thought the oblique rays were distorted by compression
of the matrix, but I find in our St. Davids specimens rectangular
and oblique spicules associated on the same surface of shale.

Dr. George F. Matthew has described and illustrated* under the
names of Protospongia ? minor and var. distans some fine, slender
spicules that appear similar to those of P. fenestrata from St. Davids,
and they occur at about the same horizon of the Middle Cambrian in
Wales and New Brunswick. I am inclined to consider that they
should be referred to P. fenestrata Salter.

Delicate cruciform spicules that I refer to this species occur in the
black shales of the Paradoxides hicksi zone in Newfoundland.

Spicules agreeing in details with those from St. Davids occur in
the shaly Lower Cambrian limestones of eastern New York? in
association with a large Lower Cambrian fauna. It is to be recalled,
however, that while individual spicules from widely separated local-
ities and stratigraphic position may be apparently similar the sponges
might have been quite different, hence specific determinations based
only on the spicules must be considered as tentative and more or less
doubtful.

To the south in Alabama similar single spicules occur abundantly
in the siliceous nodules of the Middle Cambrian Coosa formation
(89x), but none were found in the shales.

1 Trans. Royal Soc. Canada, Vol. 3, Sec. IV, 1885, Pub. 1886, p. 30, pl. V,
es 2h SE
*Tenth Ann. Rept. U. S. Geol. Survey, 1890, p. 597, pl. XT tics. 2!

306 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

On the western side of North America rectangular spicules with
slender rays occur in the Bloomington formation and also Spence
shale of Idaho in association with a large Middle Cambrian fauna.
The associated but scattered spicules vary in size from 30 mm. with
rays 15 mm. in length to rays 4 mm., 2.5 mm. and 0.5 mm. in length,
which correspond somewhat to the variations of the spicules in
typical specimens from Wales.

Cruciform spicules that may have belonged to this or an allied
species of Protospongia occur on the surface of shaly limestones of
the Middle Cambrian Marjum and Wheeler formations of the House
Range in central-western Utah.

Another Middle Cambrian locality* (57n) occurs in the Eldon
limestone of British Columbia, where somewhat distorted, scattered
spicules of this type were found on the surface of a thin-bedded layer
of limestone, which closely resemble the oblique spicules from Wales.

P. fenestrata is represented in the Middle Cambrian fauna of China
by cruciform spicules embedded in limestone, that have four slender,
round rays meeting at the center of the spicule,’ but no specimens
were found with indications of the skeleton of the sponge.

The presence of spicules resembling those of P. fenestrata in the
Ceratopyge limestone of Sweden is discussed by Moberg and Seger-
berg* and an illustration given (pl. 1, fig. 5), but with the data
available it is difficult to determine if the spicules belong to this
species or to P. hickst or an undetermined species. The same is true
of all the spicules from Swedish Cambrian strata referred to
P. fenestrata and P. hicksi.

Rauff (1894) ° notes occurrence of species at localities in Norway
and Sweden, but with only scattered spicules on which to base identi-
fication the determination of authors is necessarily tentative unless
there is a considerable amount of material and actual comparison
made of typical specimens with those from other localities.

Formation and locality—Middle Cambrian: (318h) Shales of
the Menevian at St. Davids, South Wales.

North America, Middle Cambrian. (1) (Manuel formation)
Shales of zone A of No. 7 of the Manuels Brook section,’ Manuels

* Smithsonian Misc. Coll., Vol. 53, 1908, p. 200.

* Research in China, Vol. 3, p. 60, pl. 1, fig. 4. Protospongia sp. undt.

* Med. Lunds Geol. Faltk., Ser. B, No. 2 (Aftr. Kongl. Fys. Salls. Handl.,
No. Bd2r7), 1000; p50, platy fig. 5.

*See Rauff, 1804, Palaeontographica, Vol. 40, pp. 236, 237.

5Idem, p. 236.

* Walcott, Correlation Papers—Cambrian, Bull. U. S. Geol. Survey, No. 81,
1801, p. 261.

No. 6 _ MIDDLE CAMBRIAN SPONGIAE 307

Brook, a small stream which flows into Conception Bay from the
east, near Topsail Head, Newfoundland. .

The representative of the species also occurs in the Middle Cam-
brian, St. John formation, at Porters Brook, St.'Martins, New Bruns-
wick: It is described as Protospongia ? minor by Matthew (Trans.
Royal Soc. Canada, Vol. 3, Sec. IV, 1885, pub. 1886, p. 30, pl. V,
Hes. 2, 3):

(89x) Conasauga formation ; siliceous nodules embedded in argil-
laceous shale, Livingston, Coosa Valley, Floyd County, Georgia.

(5g) Spence shale; 100 feet above Brigham formation: dark
argillaceous shales and blue-black calcareous shales, Two-Mile Can-
yon, 3 miles (4.8 km.) southeast of Malad, Oneida County, Idaho.

(57n) Eldon formation; about 3,000 feet (914.4 m.) above the
Lower Cambrian and about 700 feet (213.4 m.) above the base of a
limestone correlated with No. 4 of the Eldon limestone on Mount
Bosworth, on the northwest slope of Mount Stephen, above Field,
on the Canadian Pacific Railway; also (61b) Stephen formation ;
summit of southeast spur of Mount Odaray, 7.5 miles (12 km.) south
of Hector on the Canadian Pacific Railway, British Columbia,
Canada.

(30g) Marjum limestone about 2,350 feet (716.3 m.) above the
Lower Cambrian 2.5 miles (4 km.) east of Antelope Springs, Millard
County; also (15h) Wheeler formation; south wall of Rainbow
Valley, both in House Range, Utah.

Lower Cambrian: (38a) Limestone 2 miles (3.2 km.) south of
North Granville, on the road which turns south from the road run-
ning between that village and Truthville, 4 miles (6.4 km.) west-
northwest of Granville, Fort Ann quadrangle (U.S. G. S.), Wash-
ington County, New York.

PROTOSPONGIA HICKSI Hinde
Plate 80, figs. 3, 3a-b

Protospongia fenestrata Hicks, 1871, Quart. Jour. Geol. Soc., Vol. XX VII,
p. 401, pl. XVI, fig. 20. (Identifies spicules as belonging to P. fenes-
trata.)

Protospongia fenestrata F. RoreMER (in part), 1880, Lethaea palaeozoica,
Th. 1, p. 316, fig. 59b. (Describes and illustrates spicules from Wales.
Also a large doubtful form from Sweden.)

Protospongia fenestrata Sotias, 1880, Quart. Jour. Geol. Soc., Vol. XXXVI,
p. 362, fig. 1. (Identifies spicules as P. fenestrata.)

*Tdem, Smithsonian Misc. Coll., Vol. 53, No. 5, 1908, p. 200.
4

308 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Protospongia hicksi H1nve, 1888, British Fossil Sponges, Pt. II, p. 107, pl. 1,
figs. 2, 2a. (Describes and illustrates species.)

Protospongia hicksi Raurr, 1894, Palaeontographica, Vol. 40, p. 237. (Brief
description and distribution as far as known.)

Dr. Hinde describes this well-marked species as follows :*

Sponge probably vasiform; the portions preserved indicate that the type
specimen was at least 100 mm. in height by 75 mm. in width at the summit.
The spicular mesh is composed of robust cruciform spicules, the rays are
approximately rectangular, and nearly of a uniform thickness throughout
their length. The centers of the spicules are slightly elevated, so that they
are not strictly horizontal. The rays of the smaller spicules in the majority
of cases dip beneath those of the larger forms. Five series of squares are
present in the complete mesh, the largest are 8 mm. in diameter and the
smallest 0.5 mm.; the axes of the largest spicules are 11 mm. in length and
0.52 mm. in thickness, whilst the smallest are I mm. in length and 0.2 mm.
in thickness.

.... A comparison of this form with the type of P. fenestrata shows,
however, a very considerable difference in the thickness of the spicular rays,
sufficient to indicate it as a distinct species, which I have named in honor of
its discoverer.

In no case in this species are the points of contact of the spicules with each
other clearly shown, but the structure of the mesh appears to me to justify the
view that the spicules are cemented together where they join each other;
Prof. Sollas states, however, that they are separated and not united either by
envelopment in a common coating or by ankylosis.

Fragments of mesh and detached cruciform spicules, apparently belonging
to this species, have been discovered in Norway, Sweden, and also in Nevada,
at approximately the same geological horizon.

The specimens from the Burgess shale correspond so closely to
the description and illustrations given by Dr. Hinde that I cannot
find any reasonable grounds for considering the specimens from
the widely separated localities as representing distinct species; the
size and appearance of the spicules and meshes are similar and both
are from the Middle Cambrian. In two fragments of the outer wall
of P. hicksi there are both strong and very delicate cruciform spic-
ules, but both are more nearly similar to the characteristic spicule of
P. hicksi than to the spicules of P. fenestrata.

Dr. Hinde identifies this species from Nevada, but I find that the
Nevada spicules are smaller and the rays proportionally more
slender.

The spicules and surface of the shale are coated with a black
carbonaceous-appearing film abounding in minute crystals of pyrite.
The largest fragment of the wall is 6 by 4 cm. and gives no indication
of the form of the sponge.

* British Fossil Sponges, 1888. Pt. II, pp. 107, 108.

No. 6 MIDDLE CAMBRIAN SPONGIAE 309

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass above Field, British Columbia.

Also (61f) in the thin-bedded limestones about 350 feet (106.75
m.) higher in the same section.

DIAGONIELLA Rauff

Diagoniella RAu¥FrF, 1894, Palaeospongiologie Palaeontographica, Vol. XL,
1894, p. 248, pl. I, fig. 21.

Dr. Hermann Rauff proposed name as subgenus of Protospongia

A 4, Pas
xy
LIA

————

Fic. 7.—Diagoniella cyathiformis (after Dawson, fig. 13).

but without description, and gives Protospongia coronata Dawson as
example, also mentions P. cyathiformis Dawson.

Dawson in reviewing the Little Metis fossil sponges considers that
the diagonal arrangement of the spicules is hardly sufficient varia-
tion from Protospongia to warrant establishing the genus Diagon-
tella but he found “ other peculiarities of these species (P. coronata,
P. cyathiformis), which might fairly entitle them to constitute dis-
tinct sections of the genus.” +

I am in agreement with Rauff in placing the species with the
diagonally arranged spicules in a genus distinct from Protospongia.

1 Trans. Roy. Soc. Canada, 2d ser., Vol. 2, Sec. IV, 1896, p. 106.

310 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Diagoniella is distinguished by the diagonal arrangement of the
rhombic openings formed by large cruciform spicules ; the obliquely
arranged spicules serve to separate the genus from Protospongia and
they give the body of the sponge a very characteristic appearance.

In addition to the two species D. coronata and D. cyathiformis *
we now have D. hindei from the Middle Cambrian.

In the material I collected at Little Metis in 1888 there is a large
broken fragment of Diagoniella cyathiformis Dawson that is 15 cm.
in length and 7 cm. in width; large cruciform spicules with rays
II mm. in length form the foundation for meshes 7 to 8 mm. across,
which are subdivided by smaller rectangular spicules down to open-
ings I mm. across. This sponge is probably nearly as large as
Palaeosaccus dawsoni Hinde.”

Genotype—Protospongia coronata Dawson.

Stratigraphic range.—D. coronata and D. cyathiformis occur in a
narrow band of the Metis shale which is of Cambrian and probably
of Middle Cambrian age. D. hindei is found in the lower Io feet
(3.05) of the Burgess shale.

Geographic distribution—Shore of the St. Lawrence River at
Little Metis, Province of Quebec.

Western slope of ridge connecting Wapta Peak and Mount Field,
1 mile (1.6 km.) northeast of Burgess Pass, above Field, British
Columbia.

DIAGONIELLA HINDEI, new species
Plate 81, figs. I, la-c

General form that of a straight cornucopia flattened on the sur-
face of the shale; truncated at the top with probably a relatively
large osculum the margins of which appear to have had a number of
short, fine, thread-like spicules; the body wall is built up of cruci-
form spicules arranged in oblique encircling lines with many minute
secondary spicules; traces occur near the base of fine straight
anchoring spicules.

A large specimen has a length of 11 mm. with a width of 6 mm.
at the top; it was a third narrower before being flattened out. This
species must have occurred in large numbers, as a piece of shale 10
cm. by 18 cm. has 52 specimens flattened on its surface.

Observations.—A brown incrustation of minute spicules of pyrite
forms a thin film en all the specimens of this species in the collection ;

* Trans. Royal Soc. Canada, Vol. VII, Sec. 4, 1880, pp. 41 and 43.
"Geol. Mag., Dec. III, Vol. X, 1893, p. 56, pl. IV.

NO. 6 MIDDLE CAMBRIAN SPONGIAE Syl

it presumably represents a delicate spicular membrane formed of
minute spiculae which are so incrusted with pyrite that only traces of
them are occasionally seen; one specimen has a number of short,
minute thread-like spiculae extending from it at its base and one
definite cruciform spicule ; another has the spiculae so well preserved
along the sides near the base that the diagonal arrangement of the
spicular meshes is clearly discernible (fig. 1b), and it may be traced
over the entire body.

D. hindei differs from D. coronata Dawson* by the form of the
body and relative size of its cruciform spicules and from D. cyathi-
formis Dawson by its smaller size and minute root spicules.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation, on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of
Burgess Pass, above Field, British Columbia.

Genus KIWETINOKIA, new genus :

This genus includes three species represented by large or small
groups of displaced spicules in a more or less confused and scattered
condition on the surface of shaly or thin-bedded limestone. It is
assumed that the long, slender spicular rods belong with the cruci-
form and triradiate spicules as they are intimately associated with
them in the three species:

Reticulum.—tThe evidence afforded by specimens of K. utahensis
indicates that the skeletal elements were detached and arranged so as
to form quadrate and irregular meshes from the cruciform spicules,
the wall of the sponge being further strengthened by triradiate (pro-
diaenes ?) spicules and long slender spicular rods that probably
served as anchoring spicules. The rods of K. utahensis are solid
and papillose, while those of K. metisensis and K. spiralis are formed
of very slender spicules closely twisted together in a rope-like
strand; both types of rod are nearly the same size; another rod
includes a long stem (35 mm.) composed of 2 spicules twisted
around each other and what may be a base formed of two prongs
each of which is short and enlarged at the end (fig. ta, pl. 89) ; this
rod appears to be a form intermediate between the straight simple
rod associated with K. utahensis and the spiral rod of K. spiralis.
This sponge probably grew in the form of a sack or elongate sphere
that was anchored in the mud by long spicules; a mass of spicules

Trans. Royal Soc. Canada, Vol. VII, Sec. 4, 1880, pp. a1 and 43.

312 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

70 mm. in length and 45 mm. in width and the occurrence of large
triradiate spicules show that it grew to a considerable size.

Genotype.—Kiwetinokia utahensts Walcott.

Stratigraphic range—K. utahensis has a range of 100 feet
(30.5 m.) or more in the Marjum formation and occurs in thin-
bedded limestones of the Ophir formation of the Oquirrh range sec-
tion and the Spence shale of the Ute formation. K. spiralis is from
the Marjum formation about 600 feet (183 m.) above K. utahensis.
All of the preceding are in the central portion of the Middle Cam-
brian of the Cordilleran Province. K. metisensis occurs in Little
Metis shales, the stratigraphic horizon of which has not been fully
determined but is presumably Cambrian.

Geographic distribution.—K. utahensis occurs in the House and
Oquirrh ranges of Utah and southeast of Malad, Idaho. K. spiralis
is from the House range of Utah, and K. metisensis from Little
Metis on the St. Lawrence River, Province of Quebec, Canada.

Observations —The family relations of Kiwetinokia are rendered
very uncertain as we do not know positively that the triradiate spic-
ules belong with the cruciform spicules and long anchoring spicules ;
they all occur together but whether one or the other may have been
drifted in among the others is not easily determined. It is highly
probable that the cruciform spicules and rods belong together and
very probable that the triradial spicules belong with them as they
occur in direct association both in the Utah and Little Metis speci-
mens. Assuming that all three types of spicule belong with Kiwe-
tinokia, the genus may be placed tentatively under the Hexactinellida,
family undetermined.

The rods referred to Hyalostelia from Silurian and Carboniferous
formations * have a spiral twist but they are so unlike those from the
Cambrian that I do not think it at all probable they belong to the
same genus.

Dawson describes “ peculiarly ornamented spiral rods ”’ associated
with fragments of a large sponge (Palaeosaccus dawsoni Hinde)
in the Little Metis sponge beds. He says:

They appear as if they consisted of several very minute filaments spirally
twisted together like the strands of a rope. Each filament has a row of pro-
jecting tubercles which in the rod are definitely arranged in quincunx, so that
the general arrangement is very striking. At the distal end the rods are
slightly curved and the raised lines are more straight and assume more the
aspect of distinct fibers.

fone Hinde, British Fossil Sponges, Pt. 1, 1887, pl. 1, figs. 3, 4,5; Pt. 2, 1888,
pp. 110, 118, 120, 161.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 313

The rods are found almost exclusively on the same surface with this
sponge. They do not appear to belong to any other form in these beds. Frag-
ments of the base of the sponge show that the strands of the framework have
there an imperfect spiral arrangement, though slender, and if several of them
coalesced at the base they would assume the form of the spiral rods.*

The rods are evidently of the same general character as those
associated with species of Kiwetinokia, but are quite different in
details of structure.

KIWETINOKIA UTAHENSIS, new species
: Plate 89, figs. I, Id-e

An entire specimen of this species has not been found, but frag-
ments are sufficient to give some idea of its size and character. One
specimen (fig. 1) has a length of 70 mm. and width of 45 0 mm. with
evident loss both in length and width.

Reticulum.—tThe skeletal elements are all detached and lie in a
confused mass on the shale. Large and small cruciform spicules
(tetraxine) similar in form to those of Protospongia predominate,
but unlike the latter the surface is finely papillose ; associated with the
largest mass of cruciform spicules there are slender spicular rods
with a papillose surface ; one rod broken off at each end is 20 mm. in
length with a diameter of 0.5 mm.; a rod on a separate fragment
of shaly limestone but in association with scattered cruciform spic-
ules is 30 mm. in length; on the same surface there is one mesh intact
formed of four cruciform spicules, also several Y-shaped triradial
spicules formed of one extended branch (rhabdus?) and two short
branches (actines ?) ; some of these spicules may be compared with
protriaene spicules of the Tetractinellida* in which the cladi are
directed forward; only two cladi (branches of the ecactine) having
been developed. A similarly shaped spicule occurs in the recent
Chrotella macellata.’

The rays of the largest cruciform spicules are from 7 to 8 mm.
in length and 0.5 mm. in diameter at their base; smaller spicules with
rays 2 to 3 mm. in length and still smaller are associated with the
larger spicules. The triradial spicules (prodiaenes) of the type speci-
men are small and obscure, but on another surface of shaly limestone
the branches (actines) are from 12 to 15 mm. in length; another sur-

Trans. Royal Soc. Canada, 2d ser., Vol. 2, Sec. IV, 18096, p. 113.

2 See Rept. H. M. S. Challenger, Zool., Vol. XXV, 1888, pp. lv-lviii.

®Idem, pl. IV, fig. 5. Dr. W. J. Sollas said (p. 20) when describing the
skeleton of this species, “the protriaenes with widely diverging cladi project
their cladi into the cortex, thus contributing essentially to its support.”

314 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

face has numerous small cruciform spicules on it and sixteen small
triradial spicules.

Observations.—This species lived in the Cordilleran sea of Middle
Cambrian time, ranging as now known from central western Utah
to southern Idaho. It may be that the spicules from the type locality
in the House range of western Utah and the Oquirrh range of
northern Utah and those from southeast of Malad, Idaho, are not
from this species, but in all three localities both the triradial and
cruciform spicules are similar, all occur on the surface of shaly lime-
stone, and the stratigraphic horizon of all is.sufficiently near the
Middle Cambrian Micromitra (Iphidella) pannula zone to permit of
considering that this sponge might occur in the formations and
localities listed below.

K. utahensis differs from K. spiralis in having the associated rods
spiral and formed apparently of a number of closely combined spic-
ules twisted so as to resemble a rope.

Formation and locality—Middle Cambrian: (11q) Marjum for-
mation ; about 2,300 feet (701 m.) above the Lower Cambrian, and
660 feet (203 m.) below the Upper Cambrian, in the limestone form-
ing Ic of the Marjum formation, and (3x) about 2,200 feet
(670.6 m.) above the Lower Cambrian and 810 feet (249 m.) below
the Upper Cambrian in the limestones forming td of the Marjum
formation, both 2.5 miles (4 km.) east of Antelope Springs, in ridge
east of Wheeler Amphitheater, House Range, Millard County ; also
(3e) Ophir formation; thin-bedded limestone less than 400 feet
(121.9 m.) above the quartzitic sandstones of the Cambrian, at Ophir
City, Oquirrh Range, Tooele County, all three in Utah.

(5g) Spence shale ; 100 feet (30.5 m.) above Brigham formation;
dark argillaceous shales and blue-black calcareous shales, 155 feet
(47.2 m.) forming 4a of [typewritten] Malad section; Two Mile
Canyon, 3 miles (4.8 km.) southeast of Malad, Oneida County,
Idaho.

KIWETINOKIA SPIRALIS, new species
Plate 80, figs. 2, 2a-b
This species is represented by a few scattered cruciform spicules
associated with a number of fragments of long, slender rope-like
rods formed of closely twisted strands that appear to have been very
slender spicules etched by transverse raised bands dividing them into
sections slightly longer than wide; whether these bands formed the
base of minute spines as in the rods associated with Hyalostelia

NO. 6 MIDDLE CAMBRIAN SPONGIAE 315

gracilis Hinde* is not determinable from the specimens. No
triradiate spicules have been found in association with the rods or
cruciform spicules.

The largest cruciform spicule has rays about 1.25 mm. in length;
their surface is unknown as it has been removed by the solution of
about one-half the thickness of the body and rays ; the long spiral rods
average from 0.4 to 0.5 mm. in diameter, one broken rod has a length
of 40 mm.

This species is closely allied to Hyalostelia metissica Dawson’
by the character of the spiral rods and quadrangular spicules ; owing
to our having but one specimen of K. spiralis and that very incom-
plete no further comparisons can be made. It must be understood
that there is no connection between the rods and spicules further than
that they are associated on the surface of the thin-bedded limestone.

K. spiralis occurs about 600 feet (183 m.) higher in the House
Range section than K. utahensis. It differs from the latter in the
character of the associated slender rods (anchoring spicules). .

Formation and locality—Middle Cambrian: (10z) Marjum
formation ; about 2,900 feet (884 m.) above the Lower Cambrian and
1500 feet (457.2 m.) below the Upper Cambrian in the central part
of the limestone forming ta of the Marjum limestone, in the long
cliff about 2 miles (3.2 km.) southeast of Marjum Pass, House
Range, Millard County, Utah.

KIWETINOKIA METISSICA (Dawson)

Hyalostelia Metissica Dawson, 1889, Trans. Royal Soc. Canada, Vol. VII,
Sec. IV, p. 49, fig. 20. (Describes and illustrates species.)

Sir William: Dawson described the species as follows:

This species has not yet been seen in a perfect state or showing its general
form, It seems to have been of a specially friable or decomposable character.
The body appears as irregular patches of broken up skeleton, which, under
the lens show a confused mass of cruciform spicules large and small, slender
rods and some peculiar triradiate spicules, apparently in some cases with
oblique angles, though this may perhaps be a result of distortion, cruciform
spicules with one ray curved, and minute stellate spicules. The whole some-
what resembles, though with difference in detail, the debris of the body of the
modern Hyalonema, when crumbled and examined under the microscope.
Associated with these patches, and also found separate, are many large anchor-
ing rods of peculiar structure. They consist of several slender spicules
twisted together spirally so as to resemble a rope. Each strand has little

* British Fossil Sponges, Pal. Soc., 1887, p. 129, pl. 1, figs. 5, 5a-f.
? Trans. Royal Soc. Canada, Vol. VII, Sec. IV, 1889, p. 49, fig. 20.

316 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

tubercles externally to give greater holding power, and the whole, when well
preserved, constitutes one of the most beautiful of sponge structures. In one
or two cases the spiral threads were seen to be unwound at their proximal
ends, as if passing into the slender rods of the body of the sponge.

Observations.—This species has the same type of spiral rod as
K. spiralis, also cruciform and triradiate spicules found with
K. utahensis. The stellate spicules suggest the 5 to 9 radiate spicules
of K. utahensis. The two forms appear to belong to the same genus.

Formation and locality—Middle? Cambrian: Little Metis black
argillaceous shale, Little Metis, Province of Quebec, Canada.

Fic. 8.—Kiwetinokia metissica (Dawson). Spicules & 5, and (8a) large spiral
anchoring rod magnified. (After Dawson.)

Sub-Order DICTYONINA Zittel
Family VAUXININAE, new family

Simple or branched, elongate cylindric, crateriform or frondose
thin-walled sponges with a thin, dense dermal layer ; skeletal spicules
cemented to form a continuous framework in such a manner that
the vertical rays of each spicule (tetract) are applied to the corre-
sponding rays of opposing spicules ; each transverse ray is cemented
to the opposite vertical line of rays so as to form irregular quadran-
uglar meshes with more or less irregularly disposed spicules scattered
over the quadrules thus produced ; axial ray extends inward. Root
tuft absent or unknown.

Observations —The Vauxininae are probably the Cambrian an-
cestors of the Dictyonina of the Trias, Jurassic and Cretaceous
periods, although they differ in their thin walls and the four-rayed
spicules of the skeletal framework, three of which are on one plane
and one axial ray penetrating inward at right angles to the surface

No. 6 MIDDLE CAMBRIAN SPONGIAE 317

of the sponge. These sponges have in common with the Dictyonina
a continuous spicular skeletal framework formed by cementing
together the points of the rays, and their growth results in cylindric,
branching or flattened sponges.

The Vauxininae is represented in the Middle Cambrian by the
genus Vau.ria.

VAUXIA, new genus

Elongate, cylindric single or branching, crateriform and frondose
thin-walled sponges; skeleton formed of spicules (tetracts) bearing
two main rays that combine to form the strong vertical sides of
irregular roughly outlined quadrangles with the interspaces more or
less filled in with minute spicules of various outlines; the third ray
is slender and extends across between the vertical lines to form a
straight or slightly curved transverse boundary of the meshes; the
axial ray extends inward.

Genotype-—_V auxia gracilenta Walcott.

Stratigraphic range-—Lower 10 feet (3.05 m.) of the Burgess
shale.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Bur-
gess Pass, above Field, British Columbia.

Observations.—In form the single tubed or unbranched species
resemble the Ordovician Cyathophycus reticulatus Walcott,’ but their
spicular structure is quite dissimilar. The vertical lines seen so
plainly on Vauxia gracilenta at first sight recall those of Tuponia
lineata, but on close examination they are found to be formed of the
strong short rays of spicules arranged so as to be cemented together
at the ends of the rays; both the vertical and transverse rays may be
regularly or irregularly curved and they are slightly enlarged towards
their distal end where they unite with the rays of adjoining spicules ;
in the skeleton of V. bellula the points of the rays have been sa
cemented and embedded that they appear to be continuous and to
have a common central canal; in this condition the skeleton is similar
in appearance to the frond of the graptolite Dictyonema when it is
flattened in the shale ; there are some ray-like spicules that appear to
be slender thorny processes from the rays of the skeletal spicules.
The minute spicules of the quadrangular spaces are irregular in
form but appear to indicate triacts and tetracts with curved and

1See Mem. Pal. Reticulate Sponges, Family Dictyospongidae, 1898, Hall and
Clarke, Albany, pl. 1.

318 SMITHSONIAN MISCELLANEOUS COLLECTIONS ~— VOL. 67

undulating rays,the effect of which is to give a very irregular network
in the interspaces. As far as known, the walls were thin and only
one layer of spicules has been discovered, although in V. densa the
outer dermal membrane may have had a layer of minute spicules
embedded in it and the gastral membrane may have been similarly
provided, but there is no evidence of it. .

The presence of both simple and branching forms of V. gracilenta
and V. densa is most interesting and unusual among Cambrian
sponges. It recalls species of the recent genus Hexactinella.*

In all specimens the original siliceous matter of the spicules has
been removed and replaced either by pyrite or a black carbonaceous-
appearing material or a combination of the two.

The species referred to the genus are:

Vauxia gracilenta Walcott. Genotype
Vauxia bellula Walcott

Vausxsia densa Walcott
Vausxia dignata Walcott

VAUXIA GRACILENTA, new species
Plate 82, figs. 2, 2a-d; pl. 83, figs. 1, Ia-c

This species occurs both in the form of simple cylindric tubes
flattened on the surface of the shale or with a main tube and one or
more branches (pl. 82, figs. 2, 2a), and rarely a secondary branch
springing from a primary branch. A few examples of a thickly
branched form were collected that resemble a closely branched plant
(fig. 2c, pl. 82). Specimens preserving more or less of the thin outer
dermal layer have a dull black surface that in a reflected light is
slightly roughened by vertical and transverse lines of the spicular
skeleton beneath. When the dermal layer is not present the spicules
are finely exposed (figs. 1a-c, pl. 83) ; individual spicules are rarely
seen as they are so strongly cemented into the skeleton that even in
fragments of the sponge they do not separate on their broken and
often macerated surfaces. As far as I am able to determine the
skeleton is formed of spicules having three rays on one plane and an
axial ray that presumably extended inward; the three surface rays
are usually more or less curved with their ends fused or cemented
to the ends of the opposing rays, or to the side of one of them; this
gives a ladder-like structure to each pair of vertical rows of spicules
and the entire skeleton is formed of irregularly quadrangular meshes ;
within the meshes thus formed there is a very delicate secondary

*See Rept. H. M. S. Challenger, Zool., Vol. X XI, 1887, pls. 93, 94.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 319

irregular structure formed of minute spicules (monacts, triacts or
pentracts) with bent rays that are cemented to similar adjoining
rays or to the rays of the principal spicules; this forms irregularly
oval, round or angular openings that are only seen on well-preserved
specimens ; when the walls of the opposite sides of a tube are pressed
together by the flattening of the tube so that the spicules appear to
belong to a single thickness of the wall the structure is still more com-
plicated (pl. 83, fig. 1b). The ladder-like structure is illustrated by
fig. Ic.

Vauxia gracilenta Walcott.

Fic. 9.—Diagrammatic figure of the arrangement of the principal spicules,
the rays of which are cemented together at the points indicated by X.

The principal spicules are about 0.5 mm. across from end to end
of the rays.

Dimensions.—Single compressed tubes have a length of 80 mm.
and a width flattened on the shale of 10 mm. at the upper end or
about 7 mm. as a cylinder; one branch of a branched specimen with
slender tubes has a length of 110 mm. and a width flattened of 7
mm. (fig. 1, pl. 83) ; in another branching specimen 100 mm. in length
the branches average 2.5 mm. in width, flattened (fig. 2c, pl. 82) ;
many intermediate sized tubes occur in the collection that indicate
that the size of the tube was quite variable.

Observations.—The occurrence of hundreds of almost unbroken
specimens results from the strong spicular skeleton as a direct frac-
ture was necessary to break even a slender tube, but many of the
branches were more readily broken from the main branch; many
surfaces of shale are almost covered with the flattened branches and
single tubes especially in the layers 20 feet (6.1 m.) to 50 feet
(15. 25 m.) above the lower portion of the Burgess shale.

320 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

VAUXIA BELLULA, new species
Plate 82, figs. I, Ia-b

This species occurs as simple, elongate flattened slender tubes that
taper very gradually from the summit to the base; a few specimens
have a rather dense dermal layer resembling that of Vauxia densa,
but the larger number show the skeletal structure characteristic of
the genus, and a few exhibit it very distinctly.

Reticulum—tThe spicules forming the skeleton appear to be sim-
ilar in form to those of V. gracilenta and cemented to their opposites
in the same manner; the rays, however, are more regular and form
a more regular elongate quadrangle, and the rays have been so
uniformly cemented together that the sides of the lattice-work
are uniform and the spicules appear to have a central communicating
canal extending throughout the skeleton (fig. 1a, pl. 82). At the
summit of the body a fringe of fine, short spicules is indicated on a
few specimens.

Dimensions —The largest specimen as flattened has a length of
I15 mm. with a width of 13 mm. at the top.

Observations—This species may be compared in form with single
tubes of V. gracilenta, but it is not as slender, the dermal layer is
different, and the spicular skeleton more regular. When the spicular
skeleton is well exposed it has the appearance of the mesh-like struc-
ture of the graptolite Dictyonema, and if a fragment of it was found
similar to that represented by figure 1), plate 82, it would in all prob-
ability be referred to the Graptolitoidea.

Formation and locality——Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field, on the Canadian: Pacific Railway,
British Columbia.

VAUXIA DENSA, new species
Plate 84, figs. I, Ia-c
Sponges either simple or branched ; tubes transversely corrugated

by slight undulations or nearly smooth; dermal layer dense and
usually preserved as a dull black film that suggests a carbonaceous

NO. 6 MIDDLE CAMBRIAN SPONGIAE 321

mineral, but as that is the general appearance of nearly all the fossils
in the Burgess shale it has little significance ; where the dermal sur-
face is slightly oxidized and of a brownish color it is covered with
very minute crystals of pyrite and they are also very abundant on
the black specimens.

Reticulum.—tThe skeletal structure is usually concealed by the
dermal layer, but when that has been partially removed vertical lines
connected by slightly curved transverse lines appear and when the
dermal layer is still further removed a skeletal structure similar to
that of Vauxia gracilenta is plainly indicated, but the individual
spicules are not readily determined; on frayed edges the broken
spicules (fig. 1b, pl. 84) appear to have the same irregular curved
rays as in V. gracilenta; there is a fine transversely reticulate struc-
ture at the upper end of the specimen represented by fig. 1, which ap-
pears to have been along the margin of the osculum.

Observations —This species differs from V. gracilenta by its larger
body, thick dermal layer, and obscure skeletal structure: from
V. bellula by its undulating surface and more irregular skeletal struc-
ture, and lV’. bellula is not known to have had a branching form of
growth.

VAUXIA DIGNATA, new species
Plate 81, figs. 2, 2a-c

This is a branching sponge closely allied to V. gracilenta in form
and size. The main skeletal structure is of the same type but much
more irregular; the dermal layer is thick and made up largely of
minute irregular spicules obscured by a film-like covering; it is
roughened by irregular inosculating and branching more or less
vertical ridges that give the surface much the appearance of that of
Ventriculites of the Cretaceous; some of the minute spicules recall
those of the surface of Callopegma, but this is a superficial resem-
blance although the general form of the skeletal frame-work is not
unlike that of Rhagadinia also of the Cretaceous.’

Specimens of this species are rare, only two having been collected.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge

‘ Zittel. Text-book of Pal., Eastman Ed., 1913, pp. 53, 54, 66.

322 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field, on the Canadian Pacific Railway,
British Columbia.

VAUXIA (?) VENATA, new species
Plate 85, figs. 1, ta-b

Broad turbinate or bowl-shaped, thin-walled sponge, expanding ~
above into a broadly undulated margin. Skeletal spicules cemented to
form a very fine continuous framework by the union of the ends of
the rays of the opposing spicules; the openings in the framework
are very irregular, although the vertical lines formed by the union of
the rays are fairly direct; this arises from the irregular disposition
of the transverse rays and the interpolation of additional lines of
spicules with the expansion from the base upward; minute irregular
‘spicules or curved spine-like extensions from the skeletal spicules
form a fine irregular mesh in the lattice work spaces, especially when
the thin outer siliceous dermal layer is well preserved.

Dimensions.—On the largest specimen the distance from the base
to the margin is 60 mm. and the indentations on the margin about
30 mm. apart; the vertical lines of the skeleton average about five to
the millimeter.

Observations—This is the largest expanded form of the Vausxia
group of sponges. Its form and minute skeletal mesh serve to dis-
tinguish it from all other species. The raised vertical lines of the
skeleton are very distinct on some portions of the surface, standing
out clearly, although covered with a delicate dermal film.

The form of the full-grown sponge is somewhat doubtful, as the
fossil specimens are almost completely flattened on the shale, but the
basal portion of the specimen illustrated indicates that it was bowl-
shaped with an undulating margin.

Family OCTACTINELLIDAE Hinde

Dr. Hinde’ in discussing the genus Astraeospongia Roemer said:

The spicules of this genus are so distinctly marked off from those of any
other group of Sponges that in my opinion they characterize a separate sub-
order. The constancy and the regular disposition of the six horizontal rays,

* British Fossil Sponges, Pt. II, 1888, p. 134.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 323

and the additional rays of the vertical axis, clearly show that the genus cannot
be ranked with the Hexactinellidae. The same features likewise distinguish
it from any of the genera included in the Heteractinellidae, though some of
the spicules of Tholiasterella, consisting of six horizontal rays and a vertical
ray, bear a certain resemblance to those of Astraeospongia (pl. VII, figs. Ic,
1d). But in Tholiasterella the horizontal rays are very inconstant, varying
from five to nine in number, and further, their mode of union with each other
also indicates the absence of any real affinity betwen these groups.

Rauff* regards the establishment of this sub-order as doubtful,
but with the presence of the type in Cambrian time with the same
form of spicule I think we are justified in recognizing it as a long
established group of sponges characterized by a fixed form of
spicule unknown in other sponges except as one of several forms
found in some genera of undetermined ordinal relations.

The genus Astraeospongia first appears in the Silurian (Niagara)
and extends up into the Devonian. The discovery of the new genus
Eiffelia extends the range of the sub-order Octactinellidae to the
Middle Cambrian and affords another proof of the primitive charac-
ter of the sponges of this group.

Genus EIFFELIA, new genus

Spheroidal or irregularly globular form with six-rayed skeleton
elements forming a close irregular mesh; stellate hexatins with the
rays on one plane and a vertical ray.

Genotype.—Etffelia globosa Walcott.

Stratigraphic range—lLower 10 feet (3.05 m.) of the Burgess
shale.

Geographic distribution—Western slope of ridge connecting
Wapta Peak and Mount Field, 1 mile (1.6 km.) northeast of Burgess
Pass, above Field, British Columbia.

Observations —Etfelia differs from Astraeospongia Roemer’ in
being formed of a relatively thin layer of spicules, more or less regu-
larly arranged in an outer layer, while the spicules of Astraeo-
spongia form an almost solid inner skeleton. Among living genera
of the Hexactinellidae species of Pheronema* have the general form
of Eiffelia, but the latter is a very simple form and has as far as
known only one type of spicule.

I agree with Dr. George J. Hinde that Astraeospongia should
be classed under a distinct sub-order for which he proposed Octacti-

*Palaeontographica, Vol. 40, 1893, p. I71.
* Sil. Fauna des West. Tennessee, 1860, pp. 13, 14.
* Rept. H. M. S. Challenger, Zool., Vol. X XI, 1887, pl. 54, fig. 1.

324 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

nellidae.* Dr. Karl Zittel* suggests that the supernumerary rays may
result from branching, but from my study of the spicules of Astraeo-
Spongia and Eiffelia this does not seem probable.

EIFFELIA GLOBOSA, new species
Plate 86, figs. I, 1a-b

General form globular with truncated apex in which there is a
shallow concavity about one-third the transverse diameter of the
body. This outline of the form is taken from a number of com-
pressed and flattened specimens, but it is fairly correct. The surface
of the body is formed by the interlacing of large and small six-rayed
spicules, which forms a lattice-work; some of the larger stellate
spicules have a spread of 12 mm. from point to point of the rays in
flattened specimen 30 mm. in transverse diameter; the cup of one

Fic. 10 (X 6).—A spicule with central node and six rays.

specimen is lined with what appears to have been an integument in
which small spicules similar to those of the exterior surface are
imbedded. The spicules are usually flattened in the shale to such an
extent as to be little more than a film without relief and show six
rays, but in one specimen in which the spicules are preserved in
pyrite (FeS,) there is a central hexagonal disk and a convex base
to each ray which forms the body of the spicule ; the six long rays are
apparently nearly round and marked by two or more longitudinal
striae ;a few rays indicate that they had a central canal and were not
solid; the central disk has a clearly indicated protuberance at the
center and in some examples it appears as though a vertical ray had
been broken off and in others there is a hollow suggesting the break-
ing off of a portion of the disk ; these appearances clearly point to the
presence of one and perhaps two additional vertical rays, one on
each side, projecting at right angles to the six long rays.

* British Fossil Sponges, Pt. II, 1888, p. 133.
*Text-Book Pal., Eastman Ed., 1913, p. 63.

No. 6 MIDDLE CAMBRIAN SPONGIAE 325

I have not seen traces of anchoring or thread-like spicules or
anchoring filaments on the 13 specimens in the collection; several
specimens have a suggestion of a compact tissue or epidermis which
when examined with a lens is found to be formed of minute crystals
of pyrite (FeS,) which were probably formed when the sarcode of
the sponge was present.

Observations —The spiculae of this species are apparently similar
to those of the Silurian species Astracospongia meniscus Roemer * in
having six rays in one plane radiating from a central raised button-
shaped disk, and indications of one or two additional vertical rays,
one on each side of the central disk extending outward at right angles
to the plane of the six main rays. I find a specimen of A. meniscus
Roemer in the collections of the U. S. National Museum (Catalogue
No. 36955) in which a spicule 6 mm. in diameter has a central ver-
tical ray 1.5 mm. in length rising from the disk. The spicules of
A. memscus Roemer have been entirely replaced by calcite if they
were originally siliceous as probably was the case.

Six-rayed microscopic spicules probably of E. globosa have been
noted and photographed in thin sections of the Burgess shale; also
four rayed, cruciform spicules of undetermined relations.

Sub-Order HETERACTINELLIDA Hinde

Heteractinellida Hinve, 1888, British Fossil Sponges, Pt. II, 1888, pp. 096
and 168. (Proposes name as designating a new Sub-Order equivalent
to Hexactinellida Zittel.)

Dr. Hinde based this suborder on large spicules occurring in the
Carboniferous limestones, which have a variable number of rays,
ranging from 6 to 30, and disposed so as to form either stellate or
umbrella-shaped spicules that appear to have been free or partially
fused together into a skeleton.

The first genus assigned to the Heteractinellida is Tholiasterella
Hinde, which is described as follows: ’

Form of Sponge unknown; the skeleton consists of spicules, which bear a
general resemblance to the handle and ribs of an umbrella. The handle or

*Sil. Fauna des West. Tennessee, 1860, p. 14, pl. I, figs. 6, 6a-d.
? British Fossil Sponges, Pt. II, 1888, p. 168.

326 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

vertical ray of the spicule supports on its summit a variable number of rays
which radiate from it in a generally horizontal direction. A central disc of
variable proportions is formed by the union of the bases of the horizontal rays
and the upper surface of this, and the rays may be either smooth or covered
with tubercles or blunted vertical spines. In some cases spicules of an
irregular form are present, in addition to the normal umbrella-spicules.

The spicules of the body of the Sponge appear to have been aggregated
together without definite arrangement; they seem to have been mostly free
from each other, and merely held in position by the interlacing of their rays;
but in some cases the rays appear to have been partially cemented together.
The outer surface or dermal layer of the Sponge consisted of a framework
with irregular interspaces, formed by the intervening and partial fusion of the
horizontal rays of larger and smaller “umbrella” spicules, whilst the shafts
of these spicules penetrated into the interior of the Sponge.

Zittel* places Tholiasterella among the genera of undetermined
relations, but I think it is desirable to at least bring it with Aster-
actinella Hinde* and the Middle Cambrian genus Chancelloria under
Heteractinellida as a subordinal term. The spicules of Chancelloria
are not quite so abnormal as those of Asteractinella, but they ap-
parently have the characteristics of those of Tholiasterella in the 6 to
9 rays on one plane with an axial ray at right angles to them.

Zittel, commenting upon Hinde’s Heteractinellida, concluded that
as the suborder was based on isolated spicules of undetermined rela-
tionships to the body of the sponge and hence to other known orders
of the Spongiae its systematic position was in doubt; he therefore
treated Heteractinellida as incertae sedis and said that it may perhaps
best be regarded as an aberrant Hexactinellid” By the discovery of
practically entire specimens of Chancelloria showing the Tetrac-
tinellid arrangement of the spicules in the cortex Zittel’s suggestion
is no longer tenable. The form of the spicules distinguishes Chan-
celloria from the Tetractinellida and the structure of the spicular
skeleton from the Hexactinellida. With these points taken into con-
sideration, I think that Hinde’s conclusion that a distinct subordinal
group is represented by the spicules from the Carboniferous is sus-
tained, also that Chancelloria exhibits characters that justify includ-
ing it under a family distinct from that which would include Tholias-
terella Hinde and Asteractinella Hinde.

‘Text-book Pal. Eastman Ed., 1913, p. 62.
* British Fossil Sponges, Pt. II, 1888, p. 172.
*Text-Book Pal. Eastman Ed., 1913, p. 63.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 327

Family CHANCELLORIDAE new family

With tough ectosome and dense choanosome. Spicules not united
to form a coherent skeleton. Spicules (megascleres) typically with
a central disk, six rays essentially in one plane and an axial ray;
various modifications of this form occur that result in from 4 to 9
rays in one plane, and the disappearance of the axial ray in many
spicules.

Genus Chancelloria Walcott.

CHANCELLORIA, new genus

General form elongate, tubular or finger-shaped, or broad and
frondose. All of the specimens are flattened in the shale and most of
them appear to have been more or less broken. Spicules distributed
irregularly in the outer dermal layer (ectosome), also in an interme-
diate layer and an inner layer (choanosome). No microscleres have
been observed. Large spicules (megascleres) umbrella-shaped, with
4 to 9 principal horizontal rays and a central disk or vertical axis
with an inner axial ray and possibly in some species an outer ray ;
there are also marginal spicules with 2 or 3 long, slender, straight or
curved rays.

Genotype.—Chancelloria eros Walcott.

Stratigraphic range.—C. eros occurs in the lower 10 feet (3. 05 m.)
of the Burgess shale and central portion of the Ogygopsis shale of
the Stephen formation, both Middle Cambrian; C. yorkensis 1s
found in a bed of Middle Cambrian argillaceous shale of the York
formation ; C. drusilla in the Middle Cambrian Conasauga shales, and
C. libo in Middle Cambrian Conasauga formation.

Geographic distribution—C. eros was found at the Burgess Pass
fossil quarry, in Burgess shale, on western slope of ridge connecting
Wapta Peak and Mount Field, and on west slope of Mount Field
1 mile (1.6 km.) northeast of Burgess Pass above Field, also on
northwest slope of Mount Stephen above Field, British Columbia ;
C. yorkensis occurs in shales in a railroad cut alongside the city gas
house, York, York County, Pennsylvania; C. drusilla is from
Livingston, Coosa Valley, Floyd County, Georgia, and C. libo from
limestone in Murphrees Valley, Blount County, Alabama.

Observations —The presence of a well-preserved sponge of this
type is most unusual, as in the absence of a strong spicular skeleton
little more than scattered spicules were to be expected. The Burgess
shale specimens show the outline of the soft parts either as a dark

328 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

smooth surface with the spicules embedded in it or with a brownish
or rust-colored surface resulting from the oxidation of the pyrite
which has replaced the soft parts. The second species, C. yorkensts,
is preserved only as masses of spicules on the surface of the shale
that retain a little of the original outline of the sponge but the indi-
vidual spicules have been largely displaced from their natural
position in the wall of the sponge. The sponge wall was undoubtedly
a rather firm mass of soft tissue and a strong dermal layer with the
spicules arranged as in figures I, Ie, Ic, plate 88. Completely flat-
tened on the shale, the former tubular and frond shape of C. eros is
indicated by the presence of a very thin layer of shale between the two
walls that represent the opposite walls of the sponge when in a
natural state.

The occurrence of this genus in Middle Cambrian time on both
the western and eastern sides of the continent is of interest as it indi-
cates that the genus came from the Arctic regions or else extended
all around the southern shore-line of the continent.

The general form of the spicules suggests those of the Carbonif-
erous genus Tholiasterella Hinde* in having from 5 to 9 rays with
a vertical ray, but beyond this resemblance there is little in common
between them.

The spicules of the genotype, C. eros, have from 4 to 7 simple
horizontal rays and a vertical axial ray; C. drusilla has six or seven
horizontal rays (usually seven) and a vertical axial ray, while
C. libo has eight horizontal rays, two of which appear to rise as a
bifurcation of a principal ray, the presence of an axial ray is not
determinable as the concave side of the central disk is uppermost in
the few specimens of the spicules in the collection. The presence
of bifurcating rays is very important as it is a feature very strongly
developed in the Carboniferous genus Tholiasterella.’

Of all the sponges occurring in the Burgess shale those of this
genus have been the most difficult to classify. At first only frag-
ments of the dermal layer were studied, and these showed spicules
that appeared to be triaenes and referable to the Tetractinellida ;
later a specimen was collected that had the triaene-appearing spicules
and on a worn margin 6-and 7-rayed spicules with a central disk and
clearly defined structure comparable to the spicules of Tholias-
terella* Hinde of the Carboniferous system of Europe in general

1 British Fossil Sponges, Pt. II, 1888, p. 168, pls. VII and VIII.
* Idem, pl. VII, figs. 1 and 2.
* Idem, p. 168.

NO. 6 MIDDLE CAMBRIAN SPONGIAE 329

form but not in detail of structure. It may be that Chancelloria is
the Cambrian representative of Tholiasterella and Asteractinella*
Hinde, the latter being degenerate forms of the suborder.

The species referred to the genus are:

Chancelloria drusilla Walcott, Middle Cambrian (pl. 87, figs. 2, 2a-e)
Chancelloria eros Walcott, Middle Cambrian (pl. 86, figs. 2, 2a-c; pl. 88, figs.

I, 1a-f)
Chancelloria libo Walcott, Middle Cambrian (pl. 87, figs. 1, 1a)
Chancelloria yorkensis Walcott, Middle Cambrian (pl. 87, fig. 3)

CHANCELLORIA EROS, new species
Plate 86, figs. 2, 2a-c; pl. 88, figs. 1, 1a-f

General form tubular, finger-shaped or in fronds of varying out-
line ; there are twelve of the elongate and four frond-like specimens
in the collection, all of which are flattened in the shale; that they were
hollow or filled with very soft tissue is indicated by a specimen in
which the greatly reduced space between the walls is filled with a thin
layer of shale between the dermal spicular layers of the former
opposite walls.

Reticulum.—tThe skeletal spicules are not united to form a con-
nected framework but occur more or less irregularly in the walls of
the sponge. In specimens preserving the dermal layer intact only the
outlines of the spicular rays are to be seen, the spicules being -
embedded in the compact skin-like layer; when the dermal layer
has been partially removed, either before or after being embedded
in the sediment, two of the rays of each spicule are exposed with their
points extending upward (see fig. Ie, pl. 88), and it is only when the
spicules have been displaced in relation to the dermal layer that their
structure is revealed; the two exposed rays diverge at an angle of
from 80 to go degrees, and the first impression is that they represent
two actines of a triaene spicule, but displaced spicules in the outer
layer (ectosome) and flat-lying spicules in the inner layer (endo-
some) prove that the spicules have a definite body formed of a small
disk hollowed out on one side and slightly convex on the other;
some show a tubercle that in one spicule appears as though it might
have been the base of a vertical ray with a central canal; there are
from 4 to 9 rays, each of which is truncated at its inner end where
it joins the central disk, it is then expanded and fitted closely to the
adjacent rays for a short distance; a clearly defined line delimits

* British Fossil Sponges, Pt. II, 1888, p. 172.

330 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 67

the inner end and sides of each ray within the disk ; the base of each
ray is swollen and has a shallow round pit on the upper side corre-
sponding in appearance to the hollow on the central disk; the rays
taper rapidly from where they join the body of the spicule and each
one forms a slender, straight or curved acicular ray; the rays may
be nearly on a plane or may curve downward into an umbrella-like
form; apparently there are some two or three rayed spicules with a
swollen central body, but these may be portions broken off from
many-rayed spicules. The presence of a vertical or axial ray on the
larger stellate spicules is not readily proven for, if present, they have
been crushed down into the mud and concealed or broken off ; it is the
presence of an apparently broken off base in the center of the body
that leads to the conclusion that a vertical ray existed ; there is also a
strong probability of its presence as it occurs on similar spicules in
Chancelloria drusilla.

The central body of the spicule appears to have been embedded
in the outer wall (ectosome) with its convex side towards the base
and the transverse axis horizontal or nearly at right angles to the
vertical axis of the sponge, two of its rays turned upward just
beneath this dermal outer covering and the others were embedded
in the cortex within; an inner wall of flat-lying spicules is indicated
by one specimen illustrated by figure 1f, plate 88. Tufts of fine slen-
der spicules occur along the upper margin that appear to be pressed
down with the rays of the longer spicules.

Dimensions.—The largest specimen has a length of 95 mm., with
a width as flattened on the shale of 20 mm. at its upper end and
5 mm. where broken off at the basal end. A frondlike specimen is
38 by 41 mm., and is broadly rounded at the top and almost trans-
verse at the base. The two exposed rays of the spicules in the
elongate specimen (fig. 1c, pl. 88) average from 2.5 to 3 mm. in
length in the upper half and from 1.5 to 2 mm. in the lower part; a
small-sized, six-rayed spicule, 3 mm. in diameter from the tips of the
rays, has the following proportions ; body of spicule 0.5 mm., central
disk or node 0.25 mm., length of ray from where it joins the body
to its tip 1.25 mm.; some large detached spicules have rays 10 mm.
in length, but these may belong to a separate and as yet unrecognized
species.

Observations.—This species differs from C. yorkensis in its larger
and stronger spicules, and from C. drusilla and C. libo in the form of
the spicules. It is the one species of the suborder Heteractinellida
Hinde that has its form and structure fairly well preserved.

NO.. 6 MIDDLE CAMBRIAN SPONGIAE 331

Formation and locality—-Middle Cambrian: (35k) Burgess shale
member of the Stephen formation; on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass; and (14s) Ogygopsis zone of the Stephen iorma-
tion, about 2,300 feet (7oI m.) above the Lower Cambrian and
3,540 feet (1,089 m.) below the Upper Cambrian, at the great “ fossil
bed” on the northwest slope of Mount Stephen, both above Field
on the Canadian Pacific Railroad, British Columbia.

Seven-rayed spicules indistinguishable from those of C. eros occur
above the Burgess shale in association with cruciform spicules re-
ferred to Protospongia cf. hickst on the surface of a fragment of
shaly limestone of the Middle Cambrian (61f) Stephen formation
on Mount Field, British Columbia, Canada.

CHANCELLORIA DRUSILLA, new species
Plate 87, figs. 2, 2a-e

Of this species we have the casts of scattered spicules that occur in
compact siliceous nodules ; some show only the hollow left after the
removal by solution of the siliceous spicules, and in others there is a
cast of the spicule; owing to the manner of preservation some in-
teresting details of structure are retained.

Spicules with a central disk from which six or seven rays radiate
on one plane and a vertical axial ray at right angles to the other rays ;
the central disk is hollowed out on the upper or outer side and the
inner side rises as a bulbous base for a tapering ray that may be
straight or slightly curved; this ray is the handle of the umbrella-
shaped spicules formed by the disk and horizontal rays. The hori-
zontal rays taper rather rapidly from their base to a more or less
extended aciculate distal end; in some spicules the transverse rays
appear to be on a plane but in others they tend gently downward
or inward toward the axial ray which gives the spicule an umbrella
shape ; casts of the central disk and bases of the rays indicate that the
opposite side of the central disk was concave or hollowed out and
that a spherical cavity was present on the inner end of each of the
horizontal rays. (See fig. 2a.)

The larger spicules average 7 mm. in diameter from the tips of
their rays, and smaller ones occur down to 2 mm. across.

There are many rectangular spicules of varying size with four
slender rays associated with the spicules of this species which I have
referred to Protospongia fenestrata Salter ? as it is not probable

332 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

that they belonged to the same type of sponge as Chancelloria
drusilla.

Observations —This species differs from C. eros and C. libo in the
form and structure of the spicules, and I do not know of other species
with which to compare it.

Formation and locality—Middle Cambrian: (89x) Conasauga
shales ; argillaceous shale with embedded siliceous nodules, Living-
ston, Coosa Valley, Floyd County, Georgia.

CHANCELLORIA LIBO, new species
Plate 87, figs. I, Ia

Of this species only a few spicules are known; they are on the
surface of a weathered fragment of limestone and the siliceous
spicule has been entirely replaced by calcite. The outer side of the
central disk is concave and closely resembles that of C. drusilla, the
inner side has not been seen; there are four strong horizontal rays
radiating from the disk and two pairs of smaller rays on opposite
sides of the disk that appear to be the representatives of two large
rays that have bifurcated close to the central disk, the branches of
which extend outward nearly parallel to each other. These spicules
appear to be congeneric with those of Chancelloria eros and C.
libo, and to differ from both in the arrangement of the rays.

Formation and locality—Middle Cambrian: (89) Conasauga for-
mation; limestone in Murphrees Valley, Blount County, Alabama.

CHANCELLORIA YORKENSIS, new species
Plate 87, fig. 3

Of this species there are two specimens indicating a similarity in
outline to the elongate slender forms of C. eros (pl. 88, figs. 1, 1d)
and several fragments of what were evidently pieces of the dermal
layer. In all specimens the material that replaced the original cor-
tex has been removed by solution, including the spicules (megas-
cleres) which are now represented by their molds ; these indicate that
the general character and form of the spicules was essentially the
same as those of C. eros except that most of the rays are more slen-
der except for an occasional spicule that has rather thick, rounded
curved rays. The spicules were all displaced, more or less broken
and pressed down in the calcareous mud to such an extent that only
the information gained by the study of the fine material representing
C. eros enables me to recognize their form; the greater number are

No. 6 MIDDLE CAMBRIAN SPONGIAE a3

represented by two rays curving from a base so as to resemble the
tines of a two-tined pitchfork; these appear to be fragments of six,
or more, rayed spicules that have been broken away in pairs from
the central disk.

This species is not satisfactorily preserved, but as it proves the
wide distribution of the genus it is given a specific name that indicates
the locality where it was found.

Formation and locality—Middle Cambrian: York formation;
(48) cellar diggings, corner of Penn and North Streets, city of York,
and (48d) argillaceous shales in railroad cut alongside of the Gas
House, city of York, York County, Pennsylvania.

334 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 60

Halichondrites elissa Walcott (see pl. 61)- 3-1. - eerste ee eee 270
Fic. 1. (Natural size.) A sponge flattened with its skeleton more or
less distorted and broken up on the surface of the shale.
U. S. National Museum, Catalogue No. 66447.

The specimen represented on this plate is from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

67, NO. 6, PL.

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

HALICHONDRITES ELISSA Walcott

VOL. 67, NO. 6, PL. 61

SMITHSONIAN MISCELLANEOUS COLLECTIONS

HALICHONDRITES ELISSA Walcott

No. 6 MIDDLE CAMBRIAN SPONGIAE 335

DESCRIPTION OF PLATE 61

Hahehondriies elissa Walcott (see pl.60) ic .c5 o.00 2 cock beeen ce cece ewes 270
Fic. 1. (X6.) A mat of minute spicules of the dermal layer that
were crowded out above the left upper end of the cup repre-
sented by fig. 1, pl. 60. U.S. National Museum, Catalogue
No. 66447.

Ia. (X6.) A portion of the dermal layer of the lower left side
of the preceding figure enlarged to show the finer spicules.
The specimen represented by figs. I, Ia@ is from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion, on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,

British Columbia. 7

336 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTIONJOFN PEATE G2

iupomalineata Walcott (See plss'630and) G0) 4. 5-22 nee eee 272
Fic. 1. (X 4.) Lower portion of fig. 1b, pl. 63, to illustrate oblique

crossing of vertical spicules and base of sponge. U. S.
National Museum, Catalogue No. 66448.

ta. (XX 4.) Upper end of fig. 1b, pl. 63, enlarged to illustrate the
fine waving spicules about the margin. U. S. National
Museum, Catalogue No. 66448.

tb. (> 4.) Upper end of a specimen illustrating spicules around
the margin of the osculum. U.S. National Museum, Cata-
logue No. 66449.

The specimens represented on this plate are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion, on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

VOL. 67, NO. 6, PL. 62

SMITHSONIAN MISCELLANEOUS COLLECTIONS

TUPONIA LINEATA Walcott

VOL. 67, NO. 6, PL. 63

SMITHSONIAN MISCELLANEOUS COLLECTIONS

TEE SHEEINT EGER

TUPONIA LINEATA Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 337

DESCRIPTION OF PLATE 63

Luponia lineata Walcott (see pls. 62 and 90) s 22.2.6... e eee cece ccc ceccccs 272
Fig. 1. (X3.) Portion of a flattened tube that appears to have had
fragments of other organisms drifted into it before it was
flattened in the shale. U.S. National Museum, Catalogue
No. 66450.
Ia. (X4.) Section illustrating vertical and transverse spicules.
U. S. National Museum, Catalogue No. 66451.
1b. (% of natural size.) A long slender specimen flattened in the
shale, showing general form and appearance of the sponge.
U. S. National Museum, Catalogue No. 66448.
Ic. (X2.) Enlargement of a section of specimen represented
by fig. 1b to illustrate strong and fine vertical spicules.
U. S. National Museum, Catalogue No. 66452.

338 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 64

Tuponia flexilis intermedia. Walcott. ..5.....<.-201 02-08 aces saa
Fic. 1. (Natural size.) Type specimen, showing flexible portion with
section above resembling that of 7. lineata. U.S. National
Museum, Catalogue No. 66453.
1a. (X4.) Upper portion of specimen represented by fig.’1, en-
larged to illustrate tufts of spicules at upper margin of the
sponge.
1b. (X5.) Enlargement of the surface of the central portion of
fig. I, to illustrate the vertical strands and traces of trans-
verse strands.

Tupoma bellilineata. Walcott... 2.28.0 calicte denies oo so
Fic. 2. (Natural size.) View of type specimen. U. S. National
Museum, Catalogue No. 66454.
2a. (X6.) Vertical strands.
2b. (X8.) Transverse and vertical strands.

The specimens represented on this plate are all from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia.

274

VOL. 67, NO. 6, PL, 64

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Cre ene

SABO REP
Seca? 2225 ave

ie tao BST

Le eee

* &

EO i Tats Berger

ig
a
“4

* jung: BS

tie

a flexilis intermedia Walcott

Tuponia bellilineata Walcott

Tupon

1.
2

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 65

TUPCNIA FLEXILIS Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 339

DESCRIPTION OF PLATE 65

OMEN TUT UCT NMIULCOUL , aes ais on iett Gia: For Serna abana are daveiadin’s «wes diave’arels wal obs 275
Fic. 1. (X 4.) Portion of a narrow specimen, enlarged to illustrate
the long spicules. U.S. National Museum, Catalogue No.
66781.
The specimen is on a slab with Edithella gracilens Wal-
cott.
1a. (Natural size.) Fragment of an undulating rope-like specimen
associated with specimens represented by fig. 1d. U. S.
National Museum, Catalogue No. 66455.
1b. (Natural size.) The upper portion of a long specimen showing
indications at the summit that it was originally a cylinder.
U. S. National Museum, Catalogue No. 66457.
1c. (Natural size.) The lower portion of the specimen represented
by fig. 10.
Id. (Natural size.) Surface of shale on which this species is
matted down along with fragments of Protospongia, etc.,
and associated with specimen represented by fig. 1a. U.S.
National Museum, Catalogue No. 66456.

The specimens represented on this plate are all from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion, on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

340 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 66

Wapkia grandis Walcott (see pls. 67 and’ 68) :..-...0......255-bee eee 270
Fic. 1. (Natural size.) A slender specimen, flattened on the shale. On
the right side the upper wall is exfoliated so as to disclose
portions of the opposite wall. For detailed structure see
enlargement of the upper portion of this specimen on pl. 67.
U. S. National Museum, Catalogue No. 66458.

2. (x 4.) Enlargement of the surface of a specimen to illustrate
the strong vertical spicules, transverse spicular strands and
mat of fine transverse spicules. U.S. National Museum,
Catalogue No. 664509.

3. (X<6.) Enlargement of the surface to illustrate the diagonal
spaces formed by the crossing of the spicular strands.
U. S. National Museum, Catalogue No. 66460.

67, NO. 6, PL. 66

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

me
eat

NDIS Walcott

WAPKIA GRA

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 67

WAPKIA GRANDIS Walcott

No. 6 MIDDLE CAMBRIAN SPONGIAE

341
DESCRIPTION OF PLATE 67

| PAGE

OPRABR ET ONG IsaNV alcott, (See pls: G6,;68)iz.cc. snene-c tees aeciteas vee es < 279

Fic. 1. (X< 4.) Enlargement of upper portion of fig. I, pl. 66, to illus-
trate the vertical strands that curve outward, the transverse
slightly arched strands and the mat of fine transverse
spicules. U. S. National Museum, Catalogue No. 66458.

From locality 35k, Middle Cambrian: Burgess shale member of
the Stephen formation, on the west slope of the ridge between
Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess
Pass, above Field, British Columbia.

342 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 68

Wapkia grandis Walcott.(see pls. 66, 67)... ...~.-. + 20+ 22 se, oe oe ee 279
Fic. 1. (X4.) A portion of the lower end of fig. 1, pl. 66, enlarged to

show the imbricating lamelle near the right outer margin
of the specimen. U. S. National Museum, Catalogue No.
66458.

2. (Natural size.) Specimen showing transverse strands arranged
along several vertical axes. U.S. National Museum, Cata-
logue No. 66461.

2a. (X2.) Enlargement of the upper right-hand section of the
specimen illustrated by fig. 2, to exhibit the transverse
strands and mat of fine transverse spicules.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 68

WAPKIA GRANDIS Walcott

NO. 6, PL. 69

VOL. 67,

SMITHSONIAN MISCELLANEOUS COLLECTIONS

HAZELIA PALMATA Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 343

DESCRIPTION OF PLATE 69

HiGgerinapalmae Walcott (see pl. 76, G92). Sines wi eee eck ec eee tienes 282
Fic. 1. (X2.) A transversely oval frond. U. S. National Museum,

Catalogue No. 66462.

Ia. (X2.) Frond showing arrangement of strands. U. S.
National Museum, Catalcgue No. 66463.

1b. (Natural size.) A flattened frond with irregular growth of
skeletal strands of spicules. U.S. National Museum, Cata-
logue No. 66464.

Ic. (X8.) Margin of frond represented by fig. 1a with ends of
spicular skeletal strands.

344 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESGRIPTION OF PEATE 7o

PAGE

Hazeha delicatula. Walcott (seé’pl. 90). ....... 2.025.232 dee eee 284

ERrGaemte

Id.

1b.

Ic.

Id.

Té.

Ig.

(Natural size.) A small branched specimen. U. S. National
Museum, Catalogue No. 66465.

(X 4.) Delicate vertical undulating skeletal strands. U. S.
National Museum, Catalogue No. 66466.
(< 4.) Surface with obscure skeletal strands and fine dermal
spicules. U.S. National Museum, Catalogue No. 66467.
(x 6.) Surface of dermal layer with spicules and only a slight
trace of skeletal strands. From specimen represented by
fig. Id. U.S. National Museum, Catalogue No. 66468.

(Natural size.) An upright elongate rounded frond broken
off at the base. U. S. National Museum, Catalogue No.
66468.

(Natural size.) An unusually large frond. U. S. National
Museum, Catalogue No. 66469.

(< 6.) Enlargement of the surface of specimen represented by
fig. Te.

(Natural size.) Portion of a frond with thickened margins.
U. S. National Museum, Catalogue No. 66470.

All of the specimens represented on this plate are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia.

NO. 6. PL.

VOL. 67}

SMITHSONIAN MISCELLANEOUS COLLECTIONS

HAZELIA DELICATULA Walcott

67, NO. 6, PL. 71

vOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Hazelia obscura Walcott
2. Hazelia grandis Walcott
3.. Hazelia nodulifera Walcott

mds:0>% - MIDDLE CAMBRIAN SPONGIAE 345

DESCRIPTION OF PLATE 71

MIRE a MMOUESEMIAL IN AIGOLE 8 vn 5. os?s see male, obs aie per Maas didale ale eidesviereidasie 287
Fic. 1. (Natural size.) A slender elongate simple form. U. S.
National Museum, Catalogue No. 66471.
1a. (Natural size.) A slender simple form with very dense epi-
dermal layer. U. S. National Museum, Catalogue No.
66472.

Tela & BAUIRGIES: NEMCOR RG ae Bar biloe OO ORS 2 db Sem DC areca Olcre CR eCr 285
Fic. 2. (7 mm. shorter than natural size.) The dark places on the
specimen represent the mineralized wall of the sponge;
traces of the reticulate skeletal structure are to be seen in
the impression left by the wall of the sponge where it
is flecked off in the central portion. U. S. National
Museum, Catalogue No. 66473.

The specimen represented by fig. 2 is from locality 14s, Middle
Cambrian: Ogygopsis zone of the Stephen formation; about 2,300
feet (701 m.) above the Lower Cambrian and 3,540 feet (1,089 m.)
below the Upper Cambrian in the Ogygopsis zone of the Stephen
formation, at the great “fossil bed” on the northwest slope of
Mount Stephen, above Field on the Canadian Pacific Railroad,
British Columbia.

pee CMTE ICR ERIE. NV AICO. ho 'eia cls, folsislea disle a a ahelac ole Ge Oh o's ole ote ce Qecaenes 287
Fic. 3. (Natural size.) A small upright frond attached to the valve of

a brachiopod, Nisusia alberta Walcott. U. S. National
Museum, Catalogue No. 66474.

3a. (X 4.) Enlargement of the specimen represented by fig. 3 to
illustrate nodose surface.

3b. (X3.) Fragment of a frond with strong nodose surface.
U. S. National Museum, Catalogue No. 66475.

All of the specimens represented on this plate except fig. 2 are
from locality 35k, Middle Cambrian: Burgess shale member of the
Stephen formation, on the west slope of the ridge between Mount
Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass,
above Field, British Columbia. i

346 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 72

Sentinelia. draco "'WalcOtt.<.< ..0s8.o2 edavcetle dete 0 os Guo ie seers rere race eee eae
Fic. 1. (Natural size.) Type specimen which has suffered much from
compression and weathering on surface of a shaly lime-
stone. U.S. National Museum, Catalogue No. 66477.
From locality 58m, Middle Cambrian: Stephen formation; about
1,000 feet (305 m.) above the top of the Lower Cambrian in bluish
black and gray limestone (138 feet, 42.6 m.) of the Stephen forma-
tion, Castle Mountain section; northeast slope of Castle Mountain,
facing amphitheater, north of Canadian Pacific Railway, Alberta,
Canada.
1a. (Natural size.) Specimen tentatively referred to this species.
U. S. National Museum, Catalogue No. 66478.
From locality 3t, Middle Cambrian: Wheeler formation; about
1,700 feet (518.2 m.) above the Lower Cambrian and 2,700 feet
(823 m.) below the Upper Cambrian in the shaly limestones and
calcareous shales of the Wheeler formation, in the eastern part of
Wheeler Amphitheater, east of Antelope Springs, House Range,
Millard County, Utah.

Corralto undulata, Walcottac.%.ctweces sees cee eRe Senne eee
Fic. 2. (Natural size.) A flattened specimen preserving undulations
of growth, vertical strands of the skeletal structure, and
faint indications of the fine transverse strands; the fine
slender acerate spicules of the strands and interspaces
are not sufficiently clear to photograph. U. S. National

Museum, Catalogue No. 66479. (35k.)
2a. (Natural size.) A frond illustrating the spicular strands more
clearly than fig. 2. U.S. National Museum, Catalogue No.

66480. (35k.)

Hazelia conferta Walcott xcs <c'6 ccs = «sai ein! Mole ells aye tla hee
Fic. 3, . (Natural size.) View of type specimen illustrating compression
of a relatively soft sponge. ‘The pressing out of the
gelatinous tissue from beneath the dermal membrane is
well shown at the left side and towards the lower end.

U. S. National Museum, Catalogue No. 66476.

The specimens represented by figs. 2, 2a, and 3 are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia.

Choia carteri Walcott (see pls. 73 and 75)... ... cece ene ee cree teens teens
Fic. 4. (X6.) Fragment of specimen preserving the thatch of fine
spicules with some of the long, larger spicules. U. S.

National Museum, Catalogue No. 66481.

From locality 61j, Middle Cambrian: Stephen formation; yellow
weathering band of calcareo-argillaceous shale; west slope of Mt.
Field, near Burgess Pass ridge, about 3,000 feet (914.9 m.) above
Field on Canadian Pacific Railway, British Columbia.

288

283

292

VOL. 67, NO. 6, PL. 72

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Sentinelia draco Walcott
Corralia undulata Walcott
Hazelia conferta Walcott

Choia carteri Walcott

VOL. 67, NO. 6, PL. 73

SMITHSONIAN MISCELLANEOUS COLLECTIONS

aes

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NO. 6 _ MIDDLE CAMBRIAN SPONGIAE 347

DESCRIPTION OF PLATE 73

Cuoacumers Waleott-(see pis, 72:and 75) ce. ccccaccceenendedadave ceases 292
Fic. 1. (X2.) <A thoroughly flattened specimen with unusually well-
preserved long spicules. The lower side of disk is indi-
cated by the mat of fine spicules over the larger spicules.
U. S. National Museum, Catalogue No. 66482.

Ia. (X3.) A broken specimen showing a portion of the convex
lower side and radiating from beneath it the strong long
spicules of the upper side of the sponge. U. S. National
Museum, Catalogue No. 66483.

1b. (X3.) Three injured specimens, two showing the upper side
and one (X) the fine spicules of the lower side. U. S.
National Museum, Catalogue No. 66484.

Chora saaieys, Walcott (see plo 74, Ags. 1, Id)... csc sn sce ce cecs tease ees 204
Fics. 2, 2a. (X 4.) Disks illustrating the long spicules of the upper
side. U.S. National Museum, Catalogue No. 66486.

The specimens represented on this plate are all from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, I mile (1.6 km.) northeast of Burgess Pass, above
Fieldy British Columbia.

348 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 74

Chota ridleys Walcott. (see pl. 73, figs: 2) 20). ...2-.. 22.0120 . oe 204
Fic. 1. (X8.) Enlargement of some of the disks on the specimen
represented by fig. Ia.
Ia. (X<2.)°-A group of disks on a fragment of shales Ware
National Museum, Catalogue No. 66487.

The specimen represented on this plate is from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion, on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

VOL. 67, NO. 6, PL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

CHOIA RIDLEY! Walcott

Watcott

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SMITHSONIAN MISCELLANEOUS COLLECTIONS

No. 6 MIDDLE CAMBRIAN SPONGIAE 349

DESCRIPTION OF PLATE 75

Cae RECIFE TS VU ANGOEL 6.0 oo. sca) SARS Sal oiaun: ate orale ocdra ei acecceietls,# eee nein we e's 205
Fic. 1. (Natural size.) Weathered specimen on the surface of shaly
limestone. The fine spicules are nearly all gone, and the
large ones much damaged. U.S. National Museum, Cata-
logue No, 66488.

From locality 3y, Middle Cambrian: about 2,150 feet (655.3 m.)
above the Lower Cambrian and 2,250 feet (685.8 m.) below the
Upper Cambrian in the shaly limestones forming 1d of the Marjum
limestone, 2.5 miles (4 km.) east of Antelope Springs in ridge east
of Wheeler Amphitheater, House Range, Millard County, Utah.

Ciasanearicrs Waleote (see pls: 72°and 73) . jv ..s oot seb s ccc cee ocsjeec ven 292

Fic. 2. (6.) Lower side of a specimen with many short irregularly
arranged spicules matted down on the radiating spicules.

U. S. National Museum, Catalogue No. 66485.
From locality 35k, Middle Cambrian: Burgess shale member of
the Stephen formation; on the west slope of the ridge between
Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of Bur-

gess Pass, above Field, British Columbia.

350 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 76

Chota hindet’ (Dawson) oe2 (00252. oped os nee eee see eee

Fic. 1. (Natural size.) Edge of a large disk with large radiating
spicules. U. S. National Museum, Catalogue No. 66489.

Ia. (X6.) Enlargement of a portion of the disk with fine
spicules. U. S. National Museum, Catalogue No. 66490.

The specimens represented by figs. 1, 1a are from locality 392g,

Middle ? Cambrian (probably between the Middle and Upper

Cambrian): Black shales at Little Metis, province of Quebec,

Canada.

Hazelia palmata Walcott (see pl. 60) ......2 eee. ce es oes ee eee
Fic. 2. ( 4.) <A small frond with irregular and obliquely crossed
skeletal strands of spicules. U.S. National Museum, Cata-

logue No. 66491. (35k.)

Hamptoma bowerbanki Walcott (see pls. 77, 78)...... 2. 000.2 0.se0e onan
Fic. 3. (Natural size.) A small specimen. U. S. National Museum,
Catalogue No. 66492.

The specimens represented by figs. 2 and 3 are from locality 35k,

Middle Cambrian: Burgess shale member of the Stephen forma-

tion, on the west slope of the ridge between Mount Field and Wapta

Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

282

2907

VOL. 67, NO. 6 PL

SMITHSONIAN MISCELLANEOUS COLLECTIONS

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VOL. 67, NO. 6, PL. 77

SMITHSONIAN MISCELLANEOUS COLLECTIONS

HAMPTONiA BOWERBANKI Waicott

NO. 6 ' MIDDLE CAMBRIAN SPONGIAE 351

DESCRIPTION OF PLATE 77

Hamptonia bowerbanki Walcott (see pls. 76 and 78). ..........2.0eeee ees
Fic. 1. (X6.) Enlargement of a portion of the surface of specimen
represented by fig. 1, pl. 78, to illustrate spicules.

352 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATES

Hamptonia bowerbanki Walcott (see pls:76;, 77) <.).- 2a:->- seen eee
Fic. 1. (Reduced to one-half size.) Outline of a large sponge 200 mm.
in its greatest diameter. U. S. National Museum, Cata-
logue No. 66493.
1a. (X6.) Portion of the spicular surface of the outer portion of
a large sponge to illustrate marginal fringe of spicules.
U. S. National Museum, Catalogue No. 66494.

The specimens represented on this plate are from locality 35k,

Middle Cambrian: Burgess shale member of the Stephen forma-
tion, on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

PL. 78

NO. 6,

VOL. 67,

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SMITHSONIAN MISCELLANEOUS COLLECTIONS

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 79

1. Pirania muricata Walcott
2. Protospongia erixo Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 353

DESCRIPTION OF PLATE 79

Fy TTA CUM PILICTIC LCN ie GOES aa ake «1 « Osea ole, secsevehetere cas aielaiaie el sii! perp Daleeleles ore ois 208
Fic. 1. (X2.) A branching specimen flattened in the shale. U. S,
National Museum, Catalogue No. 66495.
ta. (X3.) Specimen split longitudinally so as to show interior
tube and walls. U. S. National Museum, Catalogue No.
66490.
1b. (X3.) A broken specimen illustrating the exterior layer of
the body. U.S. National Museum, Catalogue No. 66497.
Ic. (X2.) A fragment of the outer wall with a few long spicules
attached to it. The plate-headed spicule is shown on the
lower margin. U. S. National Museum, Catalogue No.
66408.
The specimens represented by figs. 1, Ia-c are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.
1d. (X2.) A small specimen with center crushed in and spicules
crowded toward the top. U. S. National Museum, Cata-
logue No. 66499. °

Ie. (X2.) A specimen with spicules radiating from all portions
of the surface. This may be a variety of Pirania muricata.
U. S. National Museum, Catalogue No. 66500.

The specimens represented by figs. Id and te are from locality
14s, Middle Cambrian: Ogygopsis zone of the Stephen formation ;
about 2,300 (7or1 m.) above the Lower Cambrian and 3.540 feet
(1,089 m.) below the Upper Cambrian in the Ogygopsis zone of the
Stephen formation, at the great “ fossil bed” on the northwest slope
of Mount Stephen, above Field on the Canadian Pacific Railroad,
British Columbia.

i ae OMCtG CHIVO. SEW SPECIES. .. 6.5 iid. diac cient de whee cle drieeed ee oe nase 353
Fic. 2. (X 3.) Scattered and weathered spicules on surface of lime-
stone without any mesh structure. U.S. National Museum,
Catalogue No. 15309.
2a, 2b, 2c. (X3.) Single spicules weathered out on surface of
limestone; these show variation in form, also the manner
of the union of the rays at the center. U. S. National
Museum, Catalogue No. 15300.

The spicules of this species resemble those of P. hicksi but differ
in the manner of the union of the rays at the center and in the more
rounded rays. Fig. 2 is composed of a great mass of small spicules
with a few larger ones; there is no evidence of the mesh structure
of the wall, but it was probably similar to that of other species of
the genus.

The specimens represented by figs. 2, 2a-c are from locality 55a,
Middle Cambrian: Shaly limestone at top of Eldorado limestone,
east slope of Prospect Mountain in New York Canyon, Eureka
Mining District, Eureka County, Nevada.

354

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 80

Protospongia fenestrata Salter. i....,.0%. 50. «of ws tee =[ee 3
Fic. tr. (X2.) Large, slender spicules that may have belonged to an

anchoring rope. U. S. National Museum, Catalogue No.
18377.

Ia, Ib. (X3.) Scattered cruciform spicules on surface of black
shale. U.S. National Museum, Catalogue No. 18377.

The specimens represented by figs. 1, 1a-b are from locality 318h,
Middle Cambrian: Shales in the Menevian at St. Davids, South
Wales.

2. (X 2.) Group of small spicules that have the same characters of
those of fig. 1a. U. S. National Museum, Catalogue No.
66501.

From locality 5g, Middle Cambrian: Spence shale; 100 feet
(30.5 m.) above Brigham formation; dark argillaceous shales and
blue black calcareous shales, 155 feet (30.5 m.) above Brigham
formation; dark argillaceous shales and blue black calcareous shales,
155 feet (47.2 km.), forming 4a of typewritten Malad section, Two
Mile Canyon, 3 miles (4.8 km.) southeast of Malad, Oneida County,
Idaho.

Protospongia hickst Tinde eins iiris.cc sic ie vo.0s os )sltn'= oleh te eee
Fic. 3. (Natural size.) Portion of the spicular mesh of the sponge

wall formed of the large primary and the secondary and
tertiary cruciform spicules. U.S. National Museum, Cata-
logue No. 66502.

3a. (X2.) Enlargement of the specimen represented by fig. 3.

3b. (X2.) Portion of the wall of this species matted down on
fragments of Tuponia flexilis. U. S. National Museum,
Catalogue No. 66456.

The specimens represented by figs. 3, 3a are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field on
the Canadian Pacific Railway, British Columbia.

307

PL. 80

NO.

VOL. 67,

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Protospongla fenestrata Walcott

Protospongia hicksi Walcott

1
3.

VOL. 67, NO. 6, PL. 81

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Diagonielia hindei Walcott
. Vauxla dignata Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 355

DESCRIPTION OF PLATE 81

ee OMen OU RAMEE NVALCOUL! occa siete at olen aa iite cies eie's eee ces wale as we Se 310
Fics. 1, Ia. (X3.) Enlargement of two of the specimens shown on
howe:
1b. (X4.) Enlargement of a specimen preserving some of the
cruciform spicules. U.S. National Museum, Catalogue No.
66504.
Ic. (Natural size.) Three specimens on a small piece of shale.
U.S. National Museum, Catalogue No. 66503.

CEM REP PETE NVGICOLD S51... ccle sccie eoln ws cetro ae es on wid eave Goale Baveie oe bis un 321

Fic. 2. (Natural size.) A specimen with two main branches and traces
of five others. U. S. National Museum, Catalogue No.

66505.
2a. (X 4.) Ridged surface of specimen represented by right-hand

- branch of fig. 2.

2c. (X6.) Fragment of a branch preserving rough outer surface,
also where the latter is removed the outline of the irregular
latticed skeleton. U. S. National Museum, Catalogue No.

66506.

The specimens represented on this plate are all from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field on
the Canadian Pacific Railway, British Columbia.

356 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 82

Viauwia sbellala: Walcott rec. cic 1s) eco 0.10 oo ttte eieleriolncicie ack Ce ee ee
Fic. 1. (Natural size.) A long slender tube illustrating typical form
of the species when flattened on the shale. U.S. National
Museum, Catalogue No. 66507.
ta. (Natural size.) A slender tube with the epidermal layer re-
moved so as to show the skeletal layer of spicules. U. S.
National Museum, Catalogue No. 66508.
1b. (X6.) Enlargement of the surface of fig. 1a to illustrate the
mesh-like structure of the skeletal layer and the close union
of the spicules by the cementing of the points of the oppos-
ing rays and apparent blending of the canals of the opposing
rays.

Vauxta gracilenta (see pl.-83 and text fig..0): +. .2...<.sace ee eee
Fic. 2. (X 3.) A distorted and somewhat macerated fragment of a
branching sponge. U.S. National Museum, Catalogue No.
66500.
2a. (Natural size.) A specimen having a main stem,. three
branches and one secondary branch. U. S. National
Museum, Catalogue No. 66510.
2b. (X2.) <A small branching form with secondary branches.
U. S. National Museum, Catalogue No. 66511.
2c. (Natural size.) A closely branched sponge with small branches.
U. S. National Museum, Catalogue No. 66512.
2d. (X3.) A macerated fragment showing the spicular layer.
U. S. National Museum, Catalogue No. 66513.

318

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 82

“4 2 ies

1. Vauxia bellula Walcott
2. Vauxia gracilenta Walcott

VOL. 67, NO. 6, PL. 83

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VAUXIA GRACILENTA Walcott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 357

DESCRIPTION OF PLATE 83
PAGE
Vauma gracilenta Walcott (see pl. 82 and text fig. 9)...........0.cc00ee 318
Fic. 1. (Natural size.) A large branching specimen with the base
broken away by fracture of the shale. U. S. National
Museum, Catalogue No. 66514.
Ia. (X6.) Spicular layer of a slender stem, 70 mm. in length and
6 mm. in width at the upper end. U.S. National Museum,
Catalogue No. 66515.
1b, 1c. (X6.) Spicular layer of a specimen with the outer dermal
layer removed. U. S. National Museum, Catalogue No.
66516.

The specimens represented on this plate are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field, on
the Canadian Pacific Railway, British Columbia.

358 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 84

Vauria densa-Walcott. .. cos os sevedaedeo me ces oe Cath Geter nee 320
Fic. 1. (Natural size.) A large branching form with transverse un-

dulations of growth. U. S. National Museum, Catalogue
No. 66517.

1a. (Natural size.) A slightly curved corrugated single stem, but
whether broken off from a branching form is not known.
U. S. National Museum, Catalogue No. 66518.

1b. (X6.) Enlargement of the lower portion of specimen repre-
sented by fig. 1, to illustrate the spicular structure.

Ic. (6.) Spicular layer on a specimen that has been worn or
macerated prior to its being embedded in the sediment.
U. S. National Museum, Catalogue No. 665109.

The specimens represented on this plate are all from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field, on
the Canadian Pacific Railway, British Columbia.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 84

VAUXIA DENSA Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 85

VAUXIA (2) VENATA Waicott

NO. 6 MIDDLE CAMBRIAN SPONGIAE 359

DESCRIPTION OF PLATE 85

PAA ETE ISU VV AICOLE Sor eios 2 Aslesnia Raker cays oe eas Be rtaa doe ded accede 322
Fic. 1. (Natural size.) Sponge flattened on the surface of the shale;
the base and three of the divisions of the frond are pre-
served and the base of a fourth division. U. S. National
Museum, Catalogue No. 66520.
1a, 1b. (X6.) Enlargement of a portion of the surface of the two
divisions on the left and upper side of the specimen repre-
sented by fig. 1, to illustrate the vertical and transverse
spicular strands.

The specimen represented on this plate is from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field, on
the Canadian Pacific Railway, British Columbia.

360 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 86

Etffeha. slobosa ‘Walcotts22",.\.m acieavethe sires aa 5 epee ee eo Oe eee
Fic. 1. (Natural size.) A specimen preserving something of the gen-

eral form of the body. The top margin is broken and ©

irregular. U.S. National Museum, Catalogue No. 66521.
1a. (XX 3.) A globular specimen flattened in the shale and show-
ing the shallow cup-shaped area (osculum) at the summit.
U. S. National Museum, Catalogue No. 66522.
1b. (X3.) Enlargement of a group of large and small spicules
that are flattened on the shale. U. S. National Museum,
Catalogue No. 66523.

Chancelloria eros’ Walcott: (see pl. 88) 2 v5 205.1 sce ee eee
Fic. 2. (X6.) A group of spicules preserving the shape of the body
and main rays and indications of the breaking off of the
supernumerary rays extending at right angles to the plane
of the 6 or 7 principal rays. U.S. National Museum, Cata-
logue No. 66524. (See fig. rf, pl. 88.)
2a. (X6.) Separate spicules flattened on the surface of the shale.
U. S. National Museum, Catalogue No. 66525.
The specimens represented by figs. 1, 1a-b, 2, 2a are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, on the Canadian Pacific Railway, British Columbia.
2b. (xX 4.) Portion of probable inner wall of the body flattened on
the surface of the shale with delicate spicules broken and
crushed. U.S. National Museum, Catalogue No. 66529.

2c. (X 6.) Spicules with 9 rays, a hollow on one side of the cen-
tral disk and a broken off or atrophied ray indicated on the
opposite side. U. S. National Museum, Catalogue No.
66530.

The specimens represented by figs. 2b, 2c are from locality rI4s,
Middle Cambrian: Ogygopsis zone of the Stephen formation, at the
great “fossil” bed on the northwest slope of Mount Stephen, above
Field, on the Canadian Pacific Railroad, British Columbia.

329

67, NO. 6, PL.86

VOL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

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VOL. 67, NO. 6, PL.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Pi Nee ie : s,

3. Chancelloria yorkensis Walcott
4. Takakkawia lineata Walcott

Chancelloria libo Walcott
2. Chancelloria drusilla Walcott

No. 6 MIDDLE CAMBRIAN SPONGIAE 361

DESCRIPTION OF PLATE 87

PAGE
CCE OIRO all COLE arta tiedcrs foie) oie cisieisie.sis.6:6, o'er stele eicle fvieiyehenyel wae 016 332
Fics. 1, Ia. (X3.) Partially eroded spicules on surface of limestone.
U. S. National Museum, Catalogue No. 66532. ‘
From locality 89, Upper Cambrian: Conasauga formation; lime-:
stone in Murphrees Valley, Blount County, Alabama.
REE El) OPAC TECHIE a NA GOL a ota wie cic «ints Saldic tied a.s)sie'e/ee seein t's as deans 331

Fics. 2, 2a. (X 3.) Cast of a seven-rayed spicule in siliceous nodule;
the round cavity at the base of each transverse ray is repre-
sented by a minute ball attached to the cast just outside the
margin of the central disk. U.S. National Museum, Cata-
logue No. 66533.

2b. (X3.) Cast in siliceous nodule of a spicule showing the large
axial ray and two of the transverse rays, the effect being
that of a section of an umbrella. U.S. National Museum,
Catalogue No. 66534.

2c. (X3.) Cast of a spicule showing the central disk and seven
rays. U.S. National Museum, Catalogue No. 66535.

2d. (X3.) Sketch of side view of fig. 2c to show the manner in |
which the center is elevated by the downward slope of the
rays.

2e. (X3.) Sketch of a side view of a spicule showing central disk,
axial ray and outline of transverse rays. U. S. National
Museum, Catalogue No. 66536.

The specimens represented by figs. 2, 2a-c are from locality 80x,
Middle Cambrian: Conasauga shales; argillaceous shale with em-
bedded siliceous nodules, Livingston, Coosa Valley, Floyd County,
Georgia.

Guamccioriae yorker Walcott... fico oes Lbs dels 2 bd ve sua ole 6 de viele os 332

Fic. 3. (XX 3.) _ Scattered spicules on surface of argillaceous shale.
U National Museum, Catalogue No. 66537.

The specimen represented by fig. 3 is from locality 48d, Middle

Cambrian: York formation; argillaceous shales in railroad cut

alongside of Gas House, city of York, York County, Pennsylvania.

iptrrrer MME MEO CIC OLE Acoso cakis c eerele(s cs elses Hk Teka ged Beas deinen oc 277

Fic. 4. (X2.) A nearly entire specimen. U. S. National Museum,
Catalogue No. 66539.
4a. (X3.) Specimens with vertical bands finely preserved. U. S.
National Museum, Catalogue No. 66538.
4b. (X4.) Specimen illustrating vertical bands, twisted strand
spicules and tufts of fine spicules. U.S. National Museum,
Catalogue No. 66541.
4c. (X3.) A slightly curved specimen with longitudinal spicules
displaced. U.S. National Museum, Catalogue No. 66540.
The specimens represented by figs. 4, 4a-c are from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen forma-
tion ; on the west slope of the ridge between Mount Field and Wapta
Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above Field,
British Columbia.

362

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 8&8

Chancelloria eros Walcott (see pl. 86)... oo. 0% «0s 2 ene 2
Fic. 1. (Natural size.) A long, slender specimen with the spicules

showing clearly on the outer surface. U. S. National
Museum, Catalogue No. 66526.

Ia. (X4.) Enlargement of part of the surface of fig. 1, near the
upper end to illustrate the two surface rays of the spicules:

1b. (X2.) Large broken spicules that were probably along the
upper margin of the sponge. U. S. National Museum,
Catalogue No. 66531.

The specimen represented by fig. 1b is from locality 14s, Middle
Cambrian: Ogygopsis zone of the Stephen formation; about 2,300
feet (7o1 m.) above the Lower Cambrian and 3.540 feet (1,089 m.)
below the Upper Cambrian, at the great “ fossil bed” on the north-
west slope of Mount Stephen, above Field on the Canadian Pacific
Railroad, British Columbia, Canada.

Ic. (X3.) A broken-down surface illustrating spicules with 2,
3 and 4 of their rays exposed. The 6- and 7-rayed spicules
are shown in fig. rf. U. S. National Museum, Catalogue
No. 66527.

1d. (Natural size.) The upper end of a form similar to that rep-
resented by fig. 1. U.S. National Museum, Catalogue No.
66528.

Ie. (X3.) Enlargement of the surface of fig. td to illustrate
portion of spicules showing at the surface.

If. (X 6.) Portion of what may be the inner wall of the cortex
where the rays of the spicules are on one plane and not
curved to the extent they are in the spicules of the outer
wall (ectosome). U.S. National Museum, Catalogue No.
66524. (See fig. 2, pl. 86.)

All of the specimens represented by figs. I, 1a, Ic-f are from
locality 35k, Middle Cambrian: Burgess shale member of the
Stephen formation; on’the west slope of ridge between Mount
Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass,
above Field, British Columbia.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 88

CHANCELLORIA EROS Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 6, PL. 89

1. Kiwetinokia utahensis Walcott
2. Kiwetinokia spiralis Walcott

NO. 6 - MIDDLE CAMBRIAN SPONGIAE 363

DESCRIPTION OF PLATE 89

ETB ORIN UIOHONSTS, VWAICOECs <2 oie da secs co bees sien oe eee cine ba sideceeees 313

Fic. 1. (X3.) Portion of a group of cruciform spicules that were
displaced from their natural arrangement and are now
scattered over the surface of a shaly limestone; long,
slender spicular rods occur with the same group of spicules.
U. S. National Museum, Catalogue No. 66542.

The specimen represented by ‘fig. I is from locality 11q, Middle
Cambrian: Marjum formation; about 2,300 feet (7or m.) above
the Lower Cambrian, and 660 feet (203 m.) below the Upper Cam-
brian, in the limestone forming tc of the Marjum formation, 2.5
miles (4 km.) east of Antelope Springs, in west face of ridge east
of Wheeler Amphitheater, House Range, Millard County, Utah.

Ia. (X3.) A rod formed of two long spicules twisted together
with a Y at one end formed possibly by the ends of the two
spicules of the rod; these ends or branches are enlarged
toward the end and of unequal length; there is also an
enlargement of the rod where the two branches join it.
U. S. National Museum, Catalogue No. 66452.

1b (X2.) A triradiate (protriaene) spicule from the same layer
as specimens represented by fig. 1a. U. S. National
Museum, Catalogue No. 66544.

The specimens represented by figs. Ia, 1b are from locality 3e,
aoe Cambrian: Ophir formation; Ophir City, Oquirrh Range,

tah.

Ic. (X3.) Cruciform spicules lying on the surface of limestone
shale. U.S. National Museum, Catalogue No. 66545.

1d. (X3.) A triradiate spicule associated with the spicules illus-
trated by fig. Ic.

The specimen represented by figs. Ic, Id is from locality 5¢,
Middle Cambrian: Spence shale; too feet (30.5 m.) above the Brig-
ham formation; dark argillaceous shales and blue-black calcareous
shales, 155 feet (47.2 m.), forming 4a of [typewritten] Malad sec-
tion; Two Mile Canyon, 3 miles (4.8 km.) southeast of Malad,
Oneida County, Idaho.

Ie. (X2.) Large triradiate spicules that probably belong to a
different species; numerous small, cruciform spicules occur
with them. U.S. National Museum, Catalogue No. 66546.

The specimen represented by fig. te is from locality 3x, Middle
Cambrian: Marjum formation; about 2,200 feet (670.6 m.) above
the Lower Cambrian and 810 feet (249 m.) below the Upper Cam-
brian in the limestones forming Id of the Marjum formation, 2.5
miles (4 km.) east of Antelope Springs, in ridge east of Wheeler
Amphitheater, House Range, Millard County, Utah.

RE LOREM SPUN IESE WN AIC OLE. 2.01. wereld cara mble we Sid ee vac keielee tees wees 314

Fic. 2. (X<6.) Small cruciform spicules, which are all that is known
of the body spicules referred to this species. U.S. National
Museum, Catalogue No. 66547

205 CK 20: ) Spiral rod associated ae the spicules represented by
fig. 2, illustrating the spiral structure and the spicules com-
posing it.

2b. ( X10.) Portion of two spiral rods that are associated with the
spicules represented by fig. 2.

The specimens represented by figs. 2, 2a, 2b are all on same sur-
face of one specimen, from locality 10z, Middle Cambrian: Marjum
formation; about 2,900 feet (884 m.) above the Lower Cambrian.
and 1,500 feet (457.2 m.) below the Upper Cambrian in the central
part of the limestone forming Ia of the Marjum limestone, in the
long cliff about 2 miles (3.2 km.) southeast of Marjum Pass, House
Range, Millard County, Utah.

364 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 90

Tuponia lineata Walcott (see pls. 62,63)... saci. 15m eres ae eee
Fic. 1. (Natural size.) A macerated specimen preserving four of the
longitudinal bands of spicules which project above the upper
end so as to give a peculiar appearance to the specimen,
U. S. National Museum, Catalogue No. 66777.
1a. (X3.) Enlargement of the specimen represented by fig. 1.

Hazelia delicatuia Walcott (see.ploJo)i. «ct. 2.20 ee ie ee eee
Fic. 2. (Natural size.) A small cup-shaped frond on which the open-
ings (pores) in the dermal surface are quite clearly indi-
cated. U.S. National Museum, Catalogue No. 66778.
2a. (X2.) Enlargement of the specimen represented by fig. 2.
4. (X2.) An elliptical frond with an elevated center of growth
that is somewhat doubtfully referred to this species. U. S.
National Museum, Catalogue No. 66779.

Hazelia mammillata, Walcott)... cc 2. users see sel see otek Eee ee
Fic. 3. (Natural size.) Fragment of a frond and the only specimen
now known of the species. U. S. National Museum, Cata-
logue No. 66780.
3a. (X2.) Enlargement of specimen represented by fig. 3 to more
clearly show the oscula and pores.

The specimens illustrated on this plate represent the additional

material of special interest collected in July, 1919. They are from
locality 35k, Middle Cambrian: Burgess shale member of the
Stephen formation; on the west slope of the ridge between Mount
Field and Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass,
above Field, on the Canadian Pacific Railway, British Columbia,
Canada.

284

286

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67,

NO. 6, PL. 90

1. Tuponia lineata Walcott
2 and 4. Hazelia delicatula Walcott
3. Hazelia mammillata Walcott

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOLUME 67, NUMBER 7

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

IV
Nos/-—NOTES ON STRUCTURE OF NEOLENUS

(WiTH PLATES 91 TO 105)

BY
CHARLES D. WALCOTT

(PUBLICATION 2584)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
DECEMBER 20, 1921

The Lord Baltimore reas

BALTIMORE, MD., U. S. 4.

CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV

No. 7—NOTES ON STRUCTURE OF NEOLENUS
By CHARLES D. WALCOTT
(WitTH PLATES 92, 94)

CONTENTS

PAGE
Moi NA ELSE CYS Ass ie ihe OR ae OP (Poa iy os ee Sia. 7 Ah 2 9 age ee 365

Notes on ventral appendages of Neolenus serratus by Messrs. E. O. Ulrich,
Rudoipu, kuedentann, and Re S.-Bassleren.<i:c snicee cas v Sac wee ate ass 366
Regarding distinctness of “ epipodites’”’ from the exopodites.......... 366
Sommments OM Precedijne MOtEg.'...Gusinge sete Soins. cacc tence cst cee ne 368
CARTEL STE IR) Ut C8, ES oe ier Poe on A 369
Stnuchire of the Tt xopodite and Epipodite: aces. 2 ace as eee cscs we ee ved 369
CESS ODOM AOL Re ARR a ea nig oe ee One ae eo 370
SMa Pe ee RL 5 ey eR ee Le BeCa crel tee dhe Sue bole se 371
Coniparison or exopodite andtepipoditessss.: .<.--+0c6 a. ss ces som 372
Mransversesectionvot the thoraxjor Neolenwus:....0.....ss-ccesc00+ss 374
Dratereyiy one GiGreyerealinl ogHaocooe becdcb 6bD Core Gaon eee toes aoe nase 374
Diagrammatic ventral view of the appendages of Neolenus........... 374
ID ayneahhes On AWG AAA OE eg eA ane diac dca cco oth Ob SOOT E Den OOeDr 375
Pe iitad aria ine Mea NUE Si. c ou12,2..t, asset wearin ¢ a Rea cle wins elareseine @ ats b0.8 376
SBIR MARY NOLCSE Pi. 2 ots. es ove cae toe ees uneie cs Sek soe 377

ILLUSTRATIONS

PAGE
Plates 092,04. ..Neolenus serratus (Rominger))s 2.20. ace. cases cess 435, 437

Text figures II, 12, 13,14. Diagrammatic views of structure of Neolenus
SOPRA SH ONOTMIN GEL) noise hee ota peeia ere Rian ve aie e Ciclo wane laces 371-375

INTRODUCTION

During the past twenty-five years I have published from time to
time preliminary results of investigations, even though I realized
that a few months’ additional work might give data for more
reliable conclusions and protect me from reasonable criticism. I
thought it better to present the data with tentative conclusions and
stimulate others to investigation rather than to wait for a time of

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, No. 7

365

366 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

relief from administrative duties. A recent contribution on “ Appen-
dages of Trilobites”’* is an example of hurried investigation under
pressure of many duties, also of indifferent illustration brought about
by conditions incident to the great world war and my absence dur-
ing publication while engaged in field-work. I regarded it as prob-
ably my last word on the subject for with a large accumulation of
notes, illustrations and fossils from the Cambrian formations it did
not seem probable that I would return to the subject again. When,
however, my old friend, Dr. Charles Schuchert, questioned the
presence of epipodites on the limbs of Neolenus,’ I decided to ask
three well-known invertebrate paleontologists to make a detailed
examination of the material and record their opinion as to whether
there was sufficient evidence to warrant the conclusion that in addi-
tion to the endopodite and exopodite of the limb of Neolenus there
was also present another element that was clearly an epipodite. The
three paleontologists, Messrs. E. O. Ulrich, Rudolf Ruedemann, and
R. S. Bassler, very generously consented to make the investigation
and their report under the title, ““ Notes on Ventral Appendages
of Neolenus,”’ is as follows:

NOTES ON VENTRAL APPENDAGES OF NEOLENUS SERRATUS

We, the undersigned, recognize, excluding antennules and caudal rami,
three kinds of appendages in Neolenus serratus, namely, endopodites, exopo-
dites, and “epipodites.” Besides these there is in specimen 58580 (pl. 18)
an appendage that Dr. Walcott interpreted as an endite or one of a smaller
set of epipodites but which we believe to be in this specimen merely the round
outer lobe of a displaced exopodite. We observed no convincing evidence of
“exites ” as a distinct kind of appendages. The parts shown in the upper half
of figure 3, plate 20 (representing specimen No. 65515) and which seem to be
the basis of the “ exites’”’ shown in diagram plate 31,’we conceive as a protopo-
dite and the next two succeeding segments of an endopodite that was dis-
placed in such a manner as to take an anterior direction and so that it lies
flat (instead of vertical as usual) in the matrix.

REGARDING DISTINCTNESS OF “ EPIPODITES’”” FROM THE EXOPODITES

In general outline—disregarding the setiferous fringe—the two sets of
appendages are essentially similar. Both consist of a larger pedunculate inner
lobe and a shorter more rounded terminal lobe. The outline of the conjoined
lobes is rather regularly, and on the whole gently, arcuate on the anterior side,
but the opposite edge or fringed side is biarcuate with an angular indentation
at the point of articulation between the two lobes. However, it is to be
observed that the specimens show considerable variation in the form, or rather

1 Smithsonian Misc. Coll., Vol. 67, No. 4, pp. 115-216, Dec., 1918.
7 American Journ. Sci., Ser. 4, Vol. 47, 1919, p. 231.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 367

outline, of these appendages. This seems due mainly to differences in the
angle that the relatively flat bodies held at the time of entombment to the
plane of sedimentation and to consequent modifications produced by the
compression in the outline which, of course, represents a vertical projection.
There doubtless also was some original difference in the form and size of the
bodies depending on their relative position in the animal. The size of the
exopodites increases in anterior direction to the front of the thorax.

Now, as to structural differences between the two sets of appendages:

(1) In the exopodites the surface of the lobes is plain and even, but under
the lens shows minute anastomosing subimbricating (“terrassen”) lines with
a dominant transverse direction—such as are commonly found on tests of
crustaceans. No traces of such lines are observable in the epipodites.

(2) The setiferous fringe in the exopodites consists of two distinctly
separate and different parts, one arising from the edge of the proximal, the
other from the edge of the distal lobe. The fringe on the posterior edge of
the main or larger lobe consists of lonz, closely approximated, now flat and
laterally in contact, band-like fimbrie or sete, which at a minimum are as
long as the width of the body of the lobe and may reach twice that length.
These fimbriz seem to have been firmly attached to the lobe and without any
basal coritraction or articulation, and they are smaller, hence more numerous
in a given space, in the posterior than in the more anterior exopodites. At the
first of the thoracic segments about 27 of these fimbriz were counted in 10
millimeters. At the last of the thoracic segments and on the pygidial appen-
dages the number increases to about 40 in the same space. This increase
in number of fimbrie is relative rather than absolute, being essentially
proportionate to the size of the exopodite. In the epipodites the corresponding
fringe consists of minute, well-separated, relatively short, cylindrical, acutely
pointed spines. The maximum length of the spines does not exceed one-sixth
the width of the lobe bearing them. In both the exopodites and the epipodites
the fringe of sete on the distal lobes is essentially of the same nature as that
on their respective proximal lobes. However, it will be observed that in both
cases the former are finer and on the exopodites also very much shorter.

(3) The surface of the epipodites exhibits no trace of the transverse
inosculating lines which are generally present on the exopodites, being, so far
as these wrinkles are concerned, entirely smooth under magnification. On the
other hand certain structures are rather clearly indicated on the epipodites
that are wholly wanting on the exopodites. Most important of these is a line
of denser substance running some distance within and parallel to the margin
of both lobes. On closer inspection small denticles are observed projecting
from one side of this inner line. From these and other corroborating facts
observed it is inferred that both surfaces of the epipodites bore two spiniferous
carine which united on the smaller lobe. Except at these carinz the walls of
the epipodites seem to have been exceedingly thin and at least more tenuous
than those of the exopodites. On account of their isolated and exposed posi-
tion, not being held together like the exopodites by long overlapping fringes
of sete, and lying between the endopodites and outside the exopodites, they
were much more liable to be lost:

These epipodites have been observed in only one specimen. This specimen
evidently shows the lateral aspect of the legs, as proven by their curvature and
the row of ventral spines on their concave sides. It also shows that the
epipodites lie in the same plane with the legs, one interpolated between each

368 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

pair of the latter and as they expose their broader sides must obviously have
held a similarly vertical position. This inference seems almost unavoidable
when we consider further that any other orientation of the leaf-like epipodites
would have interfered with the movement of the legs. Again, it finds support
in the fact that the marginal spines of the epipodites are found on one edge
only, and this is on the ventral side the same ‘as on the legs, which being the
exposed side is where they would naturally be expected to occur.

On the other hand, the exopodites, as indicated in all of many specimens,
were disposed horizontally. These two sets of appendages, therefore, were not
only in separate planes, but in each segment approximately perpendicular to
each other. This fact, coupled with their obvious weakness of attachment,
tenuity of substance, and their isolated and exposed position would seem
sufficiently to account for the relative infrequency of display of epipodites in
specimens preserving appendages.

Regarding the exopodites several of the specimens suggest that the setiferous
fringe is double—in other words, composed of two similar fringes, the one
underlying, the other overlying the lobes of the next posterior exopodite.

(Signed by) E. O. ULRICH.
RUDOLF RUEDEMANN.

RS: BASSEER:
June, I9I9.

COMMENTS ON PRECEDING NOTES

The painstaking, thorough study made by Messrs. Ulrich, Ruede-
mann, and Bassler in June, 1919, led them to conclude that the
difference between the exopodites and the large epipodites of the
limb of Neolenus serratus was of such a fundamental character that
the epipodites could not be considered as identical with the exopo-
dites. After reading their notes on my return in October, Ig19,
from three months’ absence in field-work I again examined the
specimens and confirmed the conclusions given in my paper of 1918?
and corroborated by the independent study of Messrs. Ulrich, Ruede-
mann, and Bassler to the effect that the ventral thoracic limb of Neo-
lenus serratus has an endopodite forming a walking leg, a large two-
jointed exopodite with fringes of long, slender filaments or fimbriae
on the large proximal joint and fine short filaments on the small distal
joint, also a large epipodite consisting of two joints resembling those
of the exopodite in form but differing radically in the marginal fila-
ments of the proximal joint, the inner lines of fine carinal spines’
and the tenuous character of the entire appendage.

They consider that the evidence for a small epipodite in the
restoration of the limb of Neolenus serratus is not sufficiently sup-

1 Smithsonian Misc. Coll., Vol. 67, No. 4, 1918, pl. 20, figs. 3, 4; pl. 21, fig. 6;
ples

* Shown in fig. 4, pl. 20 (idem), but by oversight not mentioned in text or
description of plate.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 369

ported by the one specimen supposed to show it (pl. 18, fig. 1), and
in this I am in agreement. The suggestion that the flattened lobes
on the sides of the specimen represented by figures 3 and 4, plate 20,
in advance of the endopodites and epipodites might be an exite
attached to the protopodite was made only as a possible interpreta-
tion, and I cannot differ seriously with Dr. Schuchert or Messrs.
Ulrich, Ruedemann, and Bassler in their conclusion that the so-called
lobes (exites) represented only a protopodite and displaced seg-
ments of one or more endopodites. This is a fair interpretation of
the specimen and in future restorations of Neolenus serratus both
the suggested and so-called small epipodites and exites should be
eliminated.

I here wish to express my sincere appreciation of the work of
Messrs. Ulrich, Ruedemann, and Bassler, in their study of the
material representing the ventral appendages of Neolenus serratus.

CORRECTION

In description of figure 1, plate 22, mention is made of the ends
of three epipodites projecting beyond the exopodites. The removal
of some of the overlying exopodites shows that the supposed distal
joints of epipodites are distal joints of exopodites. The most impor-
tant feature of this figure is the position of the exopodites above the
endopodites which are seen projecting backward from beneath the
fringes of the exopodites. This character is also shown by figures
1-3, plate 19, and figure 6, plate 21.

STRUCTURE OF THE EXOPODITE AND EPIPODITE

The unsatisfactory reproduction of most of the illustrations of the
1918 paper on the “Appendages of Trilobites ’’ has led to the making
of new photographs of what may be termed the critical specimens
of the exopodite and epipodite, several of which are reproduced on
plate 92 of these notes. Figure 1 represents the two upper epipodites
of figure 3, plate 20, of the 1918 paper’ as clearly as it was possible
for Dr. R. S. Bassler to photograph them; in figure 2 the spines of
the carinae and the fine filaments on the outer margin have been
brought out in relief by darkening the background; figures 3 and 3a
represent an attempt by Mr. L. W. Beeson, Chief Photographer of
the U. S. National Museum, to bring out more definite detail of the

* Smithsonian Misc. Coll., Vol. 67, No. 4, Dec., 1918.
? Smithsonian Misc. Coll., Vol. 67, No. 4, 1918, pl. 20.

370 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

upper epipodite of figure 1. He has succeeded in securing a little
more clearness but it is practically impossible to photograph and
then reproduce the original more clearly than on plate 92. Figure 4
is a photographic enlargement of the lower epipodite of figure 4,
plate 20, of the 1918 paper. I have outlined the carinae and the short
spines as they are indistinct in figure 4, plate 20. These figures, 1-4,
show quite a different structure for the epipodite from that of figures
5 and 6 of the exopodite. The general form of the joints in the two
is roughly similar as they occur flattened and somewhat distorted
in the shale.

Exopodite—tThe exopodites represented by figure 6, plate 92,
have been shortened and transversely wrinkled by compression, and
the distal lobe pushed down. I think the normal outline of the
proximal joint of an exopodite was similar to that represented by
figure 6, plate 21 (loc. cit.), and for the distal joints, by figure 1,
plate 23 (loc. cit.). I have endeavored to represent the form of the
exopodite in text figure 13 and on plate 92 of this paper.

The filaments in the compressed specimens (pl. 92, figs. 5, 6) of
the large proximal joint appear to be flat with rounded ends and round
or cylindrical near where they are inserted into a sheath or socket in
the posterior margin ; the probabilities are that in their natural condi-
tion they were rather strong, slender tubes similar in general form
and function to the branchial filaments of the lobster (Homarus
americanus H. M. Edw.) or of Meganyctiphanes norvegica M. Sars
in which the filaments are inserted along the thin margin of the
epipodite of the thoracic appendages in a manner comparable with _
those of the exopodite of Neolenus. The epipodite of Diastylis sty gia
G. O. Sars, of the order Cumacea has branchial lamellae of a some-
what similar form.

The filaments of the distal joints are inserted along the ventral
and outer margin. They are proportionally much shorter and more
slender and needle-like than those of the proximal joint and are
more like the slender spines that occur on the ventral edge of the
joints of the endopodite. :

The proximal joints of the exopodites of figure 6, plate 92, have
been shortened and transversely wrinkled by lateral compression, and
they also give the erroneous impression that the sheaths of the
filaments extended nearly across the joint.

A diagrammatic outline of a portion of the body and filaments
of a proximal joint of an exopodite is shown by text figure It.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 371

Epipodite—tThe specimens of the epipodite of Neolenus were
thoroughly studied by Messrs. Ulrich, Ruedemann, and Bassler, and
much additional information is recorded in their report. During
my recent examination a fortunate view by reflected light brought
out the interesting fact that the marginal setae or spines of the
proximal joint were inserted in the margin at the point of projection
of the minute fluting of the margin, and that they were not spinous
extensions of the exoskeleton of the epipodite. The fine spines or
sete of the “carine” are not as well preserved as those of the
ventral margin nor is the character of their insertion in the exo-
skeleton known or indicated. It may be that they were inserted in

- Fic. 11.—Diagrammatic outline of a portion of a proximal joint of a thoracic
exopodite of Neolenus. Ex ==body of joint; s= sheath into which the fila-
ments (f) are inserted.

the same manner as the row of fine spines or setae crossing some of
the endites of the trunk limbs of Apus cancriformis.

The fine spines or filaments on the lower (ventral) border of the
proximal joint appear to be similar in form to those of the margin
of the flabellum of the seventh trunk limb of Apus cancriformis or
of the gill lobe of the second limb of Apus lucasanus, These resem-
blances are merely suggestive, but they assist in the interpretation
of the fossil specimens.

The filaments or spines of the distal joint are long, fine and closely
set in along the ventral and outer edge. They appear to be propor-
tionally finer than the filaments of the distal joint of the exopodite.

A diagrammatic outline of a portion of the proximal joint of one
of the epipodites is given in text figure 12, also a vertical section

B72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
of the same; whether there were “carine” on both sides of the
epipodite as on the endites of Apus cancriformis is not fully deter-
mined, but they are so represented on the restoration (fig. 12D).
The natural side outline of the epipodite is unknown but it was
probably not very unlike that of the upper one of figure 1, plate 92.
There is no evidence that this specimen has been distorted by com-
pression or movement within the matrix; it has been flattened to
a thin film as have nearly all specimens in the Burgess shale.
Comparison of exopodite and epipodite——As already stated, the
exopodite and epipodite of Neolenus have the same general form and
if the filaments on the two were similar and the exopodite showed

Upper margin

Cad T ae ey

b a

Fic. 12.—(a) Diagrammatic outline of a portion of the proximal joint of the
epipodite of Neolenus. (b) Vertical section of fig. 12a.

traces of the presence of “ carine ” similar to those of the epipodite
there would be no question raised as to the identity of the epipodites
shown by figures 1 and 2, plate 92, and the exopodites shown by
figure 6, plate 21, and plates 22, 23 of the 1918 paper. In addition
to the epipodites being proportionally somewhat smaller and shorter,
the fringing filaments of the epipodites are quite dissimilar. It has
been suggested that the strong filaments of the exopodite have been
broken or pulled off from joints of the specimen, represented by
figure 1, plate g2. (See also figs. 3 and 4, pl. 20, of the 1918 paper.)
A study of the fringing filaments or spines of the epipodite clearly
shows that they are inserted in the margin of the exoskeleton at the
crests of the fluted margin (text fig. 12) and that the large filaments
of the exopodite are inserted between the crests (text fig. 11) and
almost touch each other at the points of insertion. In my notes of
the 1918 paper I did not pay attention to the details of structure of

NOTES ON STRUCTURE OF NEOLENUS B73

NO.

DUI] ULIpeUt ATISIOASUeI} OY} FO 489} [VSIOP oy} PUB POF Jepnonse 3y} Y

QY1B10} JY} JO SIXe dy} 0} STAASUBIZ ST UOTJIES 94} UOYM SS o19e 4nd
‘gyIpodoxod ay} JO pus jeysIp 94} YY

juo o1e (

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-odopua ay} aaoqe pue sopusojsommajd oy} FO svyFANS [VIJUDA dy} O}F JoT[ese
ynq UMOp pein} udeq savy Avut ayipodids oy} + uontsod yeinyeuun ue Ut
“(qurof (Z) puosas
-xd—='xa ‘optpodoxod 0} poyse}e ayipodids = "ga ‘ayrpodoxos 4} poy
-xO0 = '4¥I ‘opOsnUl JOXxay [esIop =" ‘fp ‘yaeay jo uorrsod = "7y
‘ssaooid yeixe—="¢ ‘D ‘# ye ssad01d pue ploy Iepnoyse = "p

LA SY MMM yy

=
SA

oe}}e S}UIO
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1

(‘FI “By 4X9} 99S)
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"bgt ‘d ‘gl 91n3y 3x9} 90g “OUT] BSAASURI} OUTeS OU} Aq yo aq yIOqG Jouues sy} Ysn

joq £1 ainsy Uy

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‘UISIVW JOlIa}ue s}I Suoye pue
x”) ssodoid pue (MD) ploy Jepnonse oy]
Jeau IO Je popun oie J9}}e]
ye st oppodids sy,
Sem d}Ipodoxs posulsy sy}
oxa pue oypodida yjog
) o}ypodiseq JO opis 0} payee Ajqeqosd
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‘JUSUINSUL [VIJUSA ==") “2
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podoxod ay} 0} poyoe
dqns A[pe}qnopun
soida1 aie ayipod

je=—9 ‘D

374 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the fringing filaments of the exopodite and epipodite as it seemed so
clear that the two were dissimilar, as shown by the figures on plates 20,
21, 23, that I decided to let the illustrations tell their own story.
There are a number of specimens showing the exopodites and
there is not one that shows evidence of a spinous “carina” or of
fringing filaments broken away from the margin of the large
proximal joint so as to give anything like the appearance of the
short marginal sete or spines of the proximal joint of the epipodite.
Transverse section of the thorax of Neolenus—Text figure 13
is a restoration of a posterior view of the appendages of the thorax
of Neolenus differing from that published in 1918* in the omission
of the small hypothetical exite and the small tentatively assumed
epipodite; there are also changes of detail in the exopodite and
epipodite. The interior boundary lines of the exopodite that were
introduced by the draftsman and overlooked have been omitted
and the character of the spines and filaments more clearly defined.
Diagram of thoracic limb.—The thoracic limb shown by the
diagrammatic outline of text figure 14 follows the interpretation of
the limb given in figure 13. The limb is straightened out so as to
present the ventral side of the coxopodite and endopodite; the fila-
ments of the exopodite are above the dorsal side of the endopodite
and the epipodite is flattened out so as to show its outline and
“carinal” spines. The exact points of attachment of the exopodite
and epipodite have not been determined, but I think they are approxi-
mately as represented in figures 13 and 14, and on plate 92.
Diagrammatic ventral view of the appendages of Neolenus——The
figure on plate 94 is drawn on the same base as the restoration on
plate 31 of the 1918 paper. The latter being unsatisfactory both
in drawing and reproduction, a new figure has been prepared in which
the small epipodite and exite of the former figure have been omitted
for reasons already given (ante p. 369), and the coxopodites,
endopodites, and large epipodites represented so as to give a clear
view of each in approximately their supposed natural position. The
endopodites are removed on the right side from six of the thoracic
limbs so as to show the exopodites with their fringe of filaments
projecting backward and overlapping; two of the cephalic limbs
have an exopodite attached, the other two and those of the postero-
cephalic limbs being omitted in order to avoid confusion; the two
exopodites on the cephalic limbs probably extended outward on a

* Smithsonian Misc. Coll., Vol. 67, No. 4, 1918, pl. 18, fig. 2.

NOTES ON STRUCTURE OF NEOLENUS 375

NO. 7
line with the endopodite, but they are represented as extending for-

ward in order to bring them out more distinctly.
Six epipodites are represented on the left side, those of the other

tnenHLILAN;

Saar Ht then98-7

Fic. 14a.—Cross section
of joints I-5.

Fic. 14.—Diagrammatic outline of
a thoracic limb.

limbs being omitted. In a natural state the epipodites were probably

situated above the endopodites and exopodites.
Exopodites of Marrella—The filaments of the anterior exopodites

of Marrella splendens Walcott* are similar in form to those of the

*Idem, Vol. 67, No. 4, 1918, p. 140.

376 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

exopodite of Neolenus serratus (Rominger), and appear to be
arranged along the margin of the joints in the same manner. These
will be further illustrated and described in a paper following this,
which it was my intention to publish as Number 5 of this volume,
but which was deferred on account of an opportunity to collect more
specimens of Marrella during the field season of 1919. Attention
is called here to the conclusion based on a large number of specimens
that the so-called epipodite of the limb of Marrella mentioned in the
paper of 1912* is formed of a number of exopodites with their fila-
ments matted down together.

AFFINITIES OF THE TRILOBITES

Dr. W. T. Calman’ in a review of my paper on the “ Appendages of
Trilobites ” calls attention to the absence of a carapace in the trilo-
bite as one of the most important differences from what the primitive
crustacean may be supposed to have been like* as he considers it
a reasonable conclusion that the fold must have been present in
the ancestral stock of the Crustacea.

I did not discuss the affinities of the trilobites at length as I wish
to consider them in connection with other crustaceans from the
Burgess shale. Attention was called to resemblances between the
ventral appendages of the trilobite and those of modern crustaceans
not so much as indicating their affinities as to show that elements
such as epipodites for instance were present both on the limb of the
trilobite and that of Anaspides.

The number of cephalic appendages for Calymene was fairly well
determined by Walcott in 1881 * from sections cut through the head,
and determined conclusively for Triarthrus by Beecher in 1895 ° and
inferentially for Neolenus by Walcott in 1918.°

* Smithsonian Misc. Coll., Vol. 57, No. 6, 1912, pl. 26, fig. 4.

* Geol. Mag., London, Vol. 6, Dec. 6, 1910, pp. 359-363.

* Idem, p. 363.

“Bull. Mus. Comp. Zool., Vol. 8, 1881, p. 201, pl. 1, and restoration pl. 6.
* American Geol., Vol. 15, pp. 93-98, pl. 4.

* Smithsonian Misc. Coll., Vol. 67, No. 4, 1918, p. 127, pl. 16.

NO. Wi NOTES ON STRUCTURE OF NEOLENUS By
SUPPLEMENTARY NOTES
(WitH PLATES 91, 93, 95-105)
CONTENTS

PAGE
are acti AC re ots Pe ey RAEN EE a ee. Cha AKA) alk io Oe lald o's ab ve givlelie Be 378
RomernCIMe MEI CIINITEY ceveh, © Se ROME ce etn ce Seiad Gio hi Se Whe saris wee dea A ole 379
RSENS eae eer ate. Tee ore ee Real oe tystcals he os cheb. ocd.e Ge vig. oecueleias ae 380
Pe AMeSN PTE eS Remm ORIG HG Won Pe ofan Pe nM Geraci ahaa Sane aac brad sip aoa Soave are wove ares 381
AtmcuMent of ventral limbs tO. @orsal fESt . 6.4.22. cess ccc cecc cues 382
PS HMUOMa OE, CIC ITEOS) IMC IIDE) oi Galtec cle sec cutss\s ccc welblae aisle ot baw areas 386
W@iaioral i Tite Dep enoe coe Soo Mo COSA See a re on See meee ee 387
Notes on individual specimens of Neolenus ..........cccceceeeecees 387
Restoration of ventral surface of Neolenus 2... ...ccccccencsccces 392

Notes on Ceraurus pleurexanthemus, Calymene senaria, and Triarthrus
Bere MR Mate Sereda 9) aa cpcveia te ale hee MO eeN Sten aha SG 6 are Sao b's. 0 9) wal 0% wie 394
eas torts MeL TSP bY ede as sens dl eR raed wre oimainios Lola we acdis.o-s 407
EEO OCIteMOUR OCIVIMENME ~ ra acia<lac cote misiaiemunlors arechene aie /elersrsteleg.crarctsvchele oe 409
EEO POGITCMO Nan GORUUIAES ta ven i ralerec ran eee ncuron aril oierateneks iallsice wesdwhhne 6 AI2
Structure of exopodite of Calymene and Ceraurus ................ 412
IB soynreraliires Voir GA Aer ai (ha US Bee ores Slo COD On anon Ob ad Se eRe are 413
Pyeidial, endopodites of: Triarthrus j<.c cc cncoccsschosececcusasodess 415
J NaI (MEO MS Se ade. bib BoB ORe ABIES IO ORE Daa Ito BOC Hae Se ae ee 415
Notes on individual specimens of Triarthrus becki Green ............. 416
Fimbriated epipodites of Calymene and Ceraurus ............c0000 00 417
Jointed epipodites of -Calymene and Ceraurus .........ccc ccc cee eeeees 419
Thoracic limbs of Neolenus, Ceraurus, Calymene, and Triarthrus ....... 420
Supposed spiral branchiz in specimen of Calymene from Ohio ......... 424
Lire! CHENG (96 SEE aa aoe ose Derod bot CORD Oo DSUICIC Cee ners Sarees 425
PNIMEtIt VA CAT alia ete ota fc lta etareete ae IC oe ne cl eye eee are 425
PND OIniinallns Tectleasseeisis sceceiste-s love eiavere Meee ol oie ore ae Aca an a oa 426
LEIS Ae al ETTGIS ES 6G 6 Gye RIEL ON Cis Oe Eve Ce cE ane ae eee 426
HEM err eI oi I gts ca clans rata Rake MCC RMA Cl ota gc 2 a lolS aca cna! s dats 427
LM ASCII Eu CUTE Ae are ose a aE Py cy 427
POE ETO Le VOAO UI 100 SWARMS. 15 w.- 0) os 10's am siteialoie caress, ehoid'« aie 'le. see gw ere vie 428
(Gascpodites and trails of trilobites@ «tat cee eect cca ole ck eke cae se cas 429
Uae TAU se ie SRSTTEE CSIP EE Se AIC ICE 1 oo) jas ave se raja e Syehe tas Bre Meee eG latelew ig Se dv wa cieiens 429
O@rdovactanimeceusta Geatio| eS act rhnsielstcjai sto ic eee cl re ielot ete Gila ecie sie dele elias: acs 430
Note on occurrence of oldest known trilobite fauna .................... 431
SMCS tT arene See tateyate Aes: oie cas aleranete eis etre aan le ahcia ie Binclovale where se. 2 432

ILLUSTRATIONS

PLATE PAGE
qrealbinihs of Weolenus, Ceraurus, and, Calymenes i: f4.sb so. es 434
oe. Limbstor Neolenus “0.6.26 cc's en. SEEK ato certo ey Deets ee ee 436
SEC CEIOISUIGE ELM ODIRE SH sls, tana asses, Geo:c, stabs cay Cems hace ma Sil Sah os we s+ 438
PREC OMS# uOie ELT OMIECS Mere, 5 cio cia) 2 (Ste gost SAR M re a emerges uted ee « 440
O7 Sections) Ob trilobites @E xopodites))) 7 asses ce aicuiers vos eicieele see cas 442
GAP SECU OES LGM MCGMO MILES: 1/0). wisn eiala cin’ <i Peis a GIES pled bend Wisleveon » De wie 444
Pe SCCELOIES POa TEN OMILESY sil) cia afoioeass Bo niche pliers sac sapahebeie ersta eee nte Ge clashed bases 446

too. Sections of trilobites (Epipodites) ..... SAE SR ees see ae Create 448

378 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

PLATE PAGE
Tox. Sections of ‘trilobites: ..2..0cee.c eens per eee ee See eens 450
102, Sections of ‘trilobites: i.e. tasireisiciee citeiere cise cininr eee acie ee ere eee 451
103. -Section’s, of ‘trilobites ssi.) Side joie ererctojee eistetefar aie ere etl ieteicie te rea 452
104. Sections of trilobites and limbs of Triarthrus .............s+scees 454
105. Longitudinal sections of Calymene senaria Green ..............4. 456
TEXT FIGURE

15. Limbs of Neolenus ici. soads Be wcue actos oa pane 383
16. Outline of transverse section of thorax of Ceraurus .............. 384
17, 17a. Outlines of portion of exopodite of Calymene ................ 410
18. Photograph .of wire Spirals’. 2 joc. acme caer ee se ceten cee AII
19, 19a. Outlines of portion of exopodite of Triarthrus............... 4iI
20. Outline of restoration of fimbriated epipodite of Ceraurus ......... AIQ

21. Thoracic limb of Neolenus, Ceraurus, Calymene and Triarthrus... 421
22. Diagrammatic outline of a coxopodite with cross sections indicated.. 422
23. Exopodite of Triarthrus becki Conrdd’ .. 2.2 5....:05. 2+ se ae 423

INTRODUCTION

The preceding notes were held in page proof during my absence
in the Canadian Rockies during the field season of 1920 in hopes
that trilobites with attached appendages might be found, but not a
fragment of an appendage was seen. In this connection it may be
of interest to state that I have collected only fourteen specimens of
Neolenus* with more or less well preserved ventral appendages. It
is, therefore, not surprising that it has not been possible to work out
complete details of structure, or that there should be differences of
opinion in relation to the interpretation of some of the specimens.
To those who can do so we extend an invitation to visit the National
Museum and study the specimens of Neolenus. The Beecher
material of Triarthrus at the Peabody Museum, New Haven, Con-
necticut, and the Walcott material of Ceraurus and Calymene at the
Museum of Comparative Zoology at Cambridge, Massachusetts, are
also accessible to students.

On my return from the field in October, 1920, I learned that a
memoir on the structure of the trilobite, by Dr. Percy E. Raymond,
was in press. This caused me to still further delay publication, in
the hope that some new evidence might be presented by Raymond.
A copy of the memoir was received in January, 1921.”

* Throughout these supplementary notes when the genera Neolenus, Caly-
mene, Ceraurus, and Triarthrus are mentioned, the species referred to are
as follows: Neolenus serratus Rominger, Calymene senaria Conrad, Cer-
aurus pleurexanthemus Green, and Triarthrus becki Green.

*The Appendages, Anatomy and Relationships of Trilobites. Mem. Conn.
Acad. Sci., Vol. VII, 1920.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 379

On application to Dr. Samuel Henshaw, Curator of the Museum
of Comparative Zoology, he generously permitted Dr. Raymond to
send me all of the Walcott sections of Calymene and Ceraurus, which
has given me the opportunity to complete the study of the slides
abandoned in 1918, and to make an unusually fine set of photographs
some of which are illustrated on plates 97, 100, 103 of these notes.

Dr. Schuchert very kindly sent me the Beecher types of Triarthrus
becki for reexamination and photographing, and I may at a future
time have some of the photographs reproduced along with new
material that may be available. -

In the preparation of the photographs I have been greatly indebted
to the cordial cooperation and skill of Dr. A. J. Olmsted, Chief
Photographer of the U. S. National Museum. Miss Frances Weiser
has carefully redrawn in ink all my pencil sketches, and Mrs. Wal-
cott has touched out many bright spots on the photographs caused
by the light reflecting from sections of minute crystals of calcite.

THE RAYMOND MEMOIR

This is a fine contribution and gives evidence of prolonged,
thorough study, keen observation, and a comprehensive grasp of
detail and the broader aspects of the subject. Students of the crus-
tacea may or may not agree with Dr. Raymond’s conclusions on the
“ Relationship of the trilobites to other Arthropoda” and “ that the
trilobite is the most primitive of the arthropods,” but they will find
the memoir presents the evidence known to him and his interpreta-
tions and generalizations with unusual clarity of statement and illus-
tration.’

This elaborate memoir clearly indicates how little we really know

of the detailed structure.of the trilobite, the small amount of material
available for study, and what a splendid opportunity there is for the
tireless investigator who will search the Paleozoic rocks of the world
for exceptional layers in deposits like those of the Burgess shale,
Utica shale and Trenton limestone.

The memoir needs an index despite its rather full table of con-
tents. It would also be more convenient for reference if the descrip-
tions of the figures on the plates each had a page reference to where
they are described or mentioned.

1 After studying the typical specimens of Neolenus serratus Rominger in
‘ which ventral appendages were preserved, Dr. Raymond wrote me under
date of February 22, 1919, and sent sketches of his interpretation of the
specimens, which is essentially the same as that given in his memoir.

380 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

I shall now comment upon a few of Raymond’s observations and
illustrations in order to present to the student a slightly different
point of view of them.’

Epipodites—In the preceding pages (pp. 366-374) reference is
made to the large epipodites of Neolenus, the evidence for the exis-
tence of which was not satisfactory to Raymond, but which is so to
Messrs. Ulrich, Bassler, Ruedemann, and Walcott. Raymond’s dia-
grammatic outlines of the “so-called epipodite” (fig. 4, p. 26)
(specimen No. 65515) was evidently drawn from the upper appen-
dage shown by figure 1, plate 92 of these notes. He failed to recog-
nize, or at least to indicate in his drawing, the well marked line of
union of the proximal and distal joints, the two carinze with their fine
spines, and that the spines on the ventral margin were unlike the
strong slender branchial tubes (filaments) of the exopodite (pl. 92,
fig. 5).

Raymond’s diagrammatic outline, figure 3, page 26, was probably
drawn from the exopodite near the center of the specimen repre-
sented by figure 6, plate 92 of these notes. His statement that the
fine “ setze”’* of his figure 4 represent fragments of the “ seta ” simi-
lar to those of the proximal and distal sections of figure 3, clearly
indicates a confused conception of the nature of the branchial fila-
ments of the exopodite and the fine slender spines of the epipodite.
The character of the branchial filaments of the exopodite is shown
in figure 5, plate 92, and text figure 11, page 371, and my interpreta-
tion of the delicate spines of the epipodite by figures 2 and 4, plate 92,
and text figure 12, page 372 of these notes.

Raymond in his memoir agrees with the view of Messrs. Ulrich,
Bassler, and Ruedemann (ante p. 366) that there is insufficient evi-
dence to establish the presence of the small epipodite and the sug-
gested exites of Walcott, in Neolenus and with Schuchert in object-
ing to the presence of the so-called exites and all epipodites large

* Throughout these supplementary notes reference to plates 91 to 105 is to
plates accompanying this paper.

Walcott 1881 refers to paper published in 1881, Bull. Mus. Compt. Zool.,
Vol. VIII, No. to.

Walcott 1918 refers to paper published in 1918, Smithsonian Misc. Coll.,
Vol. 67, No. 4, pp. 115-215.

Raymond 1920 refers to Dr. Raymond’s Memoir, Conn. Acad. Sci., Vol. VII.

* Dr. Raymond uses the term “ sete” for the lamellar elements of the exopo-
dites. Dr. W. T. Calman (Geol. Mag. Vol. VI, ro10, p. 361) in reviewing
Walcott’s paper of 1918 calls attention to his use of the term and suggests

that “the form of the elements is very different from that usually indicated
by the term sete.”

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 381

or small. His restorations of the ventral surface of Neolenus con-
sequently omit the large epipodites recognized by Walcott and
Messrs. Ulrich, Bassler, and Ruedemann.

Articular socket—Figure 2, page 24 of Raymond is an outline
sketch of two of the endopodites of Neolenus (specimen No. 58589)
in which a notch is noted (in the figure) on the lower margin of the
outer end of the proximal joint (coxopodite) and a corresponding
projection on the opposite upper margin. I did not note the “ notch ”
when studying the specimen (No. 58589) in 1917, but I now find
that it is shown in three of the limbs (text fig. 15, p. 383) at the point
of union of the coxopodite* and basipodite. Carefully reexamining
the specimen and uncovering the posterior margin of the proximal
joint of the next three anterior limbs, I found on all what appears to
be the “notch” or “articular socket of the coxopodite” of Ray-
mond, where the second joint (basipodite) unites with the first joint
(coxopodite), and that there is not a “notch” on the margin of the
coxopodite as described by Raymond on the evidence afforded by
limb marked D of our text figure 15 (specimen No. 58589). There
is a slight thickening or irregularity on the upper or anterior margin
of the coxopodite that may have been the margin of the opening for
the insertion of the muscles uniting it to the axial processes* of the
dorsal test of the axial lobe.

I have called attention to this so-called “ articular socket” of Ray-
mond, elsewhere referred to by him as a “ ball-and-socket ” joint
(p. 126), as it appears to be the evidence that led him to reverse the
natural position of the coxopodite in his restorations of Neolenus
(figure 7, p. 30, figure 8, p. 31) so that the ventral side is uppermost
and the dorsal side below, while the remaining joints of the endopo-
dite are in a natural position as shown by specimen No. 58589 (see
text figure 15) and No. 58588 (plate 93, figure 2).

Raymond states (p. 25) “ Because the spines on the endobases are
dorsal it does not follow that those on the endopodite were, for the
position of the coxopodite in a crushed specimen does not indicate

*Dr. Calman (Treatise on Zoology, Lankester, Pt. VII, 1900, p. 146) gives
a diagram of a malacostracan thoracic limb in which the coxopodite and
basipodite form the protopodite, and the exopodite is attached to the basi-
podite. As I considered that the endopodite and exopodite of Neolenus were
attached to the long proximal joint of the thoracic appendage, it followed that
I considered the proximal joint of Neolenus to be the protopodite and formed
of a combined coxopodite and basipodite. This has led to my often using
the term incorrectly.

? Walcott, 1875, Notes on Ceraurus pleurexanthemus. Ann. New York Lyc.
Nat. Hist, Vols <i, p. 162; pli XL /

382 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the position of the endopodite even of the same appendage.” The
above was written in connection with his description of specimen
No. 58589, in which the coxopodites of four cephalic limbs are
shown, also the attached endopodites. I have had photographs made
of the coxopodites and endopodites which are reproduced as text
figure 15 and figure 2, plate g1 in which it does not seem at all prob-
able that all four of the coxopodites have been reversed although
thoroughly flattened by compression in the sediment; on the con-
trary they are in a normal position in relation to the endopodite ; the
coxopodite D has the marginal spines finely preserved as shown by
figure 2, plate 91. The coxopodites of specimen No. 58588, illus-
trated by our figure 2, plate 93, clearly prove their position in rela-
tion to the endopodite, and that it is the same as in specimen No.
58589 (text figure 15).

Raymond considers that he has recognized the “ ball-and-socket ”
joint in two of Walcott’s thin sections of Calymene (slide No. 63,
figure 15, p. 53) and Ceraurus (slide No. 128, figure 17, p. 58).
The evidence for this is very unreliable, as in many sections of both
Calymene and Ceraurus a hollowing out occurs where any project-
ing point approaches closely to a fragment of what was a portion of
an appendage or a filling of the visceral cavity. This is shown in
figure 8, plate 2, Walcott, 1881, and figure 3, 4, 5, plate 91; figure 18,
plate 95, of these notes. There does not appear to be evidence either
in the specimens of Neolenus or the sections of Calymene or Ceraurus
to sustain the “ ball-and-socket ” joint theory.

Attachment of ventral limbs to dorsal test——lI inferred in 1881
that the coxopodite was attached to the ventral membrane by “a
small round process projecting from the posterior surface of the
large basal joint, and articulating in the ventral arch somewhat as
the legs of some of the Isopods articulate with the arches in the ven-
tral membrane.” This incorrect view was based on several sections
(Walcott, 1881, plate 2, figures 3 and 6; plate 3, figure 9; plate 5,
figures I and 3) where a narrow extension appears to unite the
appendage and the ventral surface. Other sections suggest that the
coxopodites of the cephalic region were attached in Calymene near
their proximal end (Walcott 1881, plate 1, figures 6, 7, 8) while
those of the therax were attached further out towards the distal end
(Walcott, 1918, plate 26, figures 6, 7).

Walcott (1918 p. 159) wrote:

The exact form of attachment to the ventral integument is unknown, but
as stated under Neolenus it was probably narrow and long and connected the

dorsal side of the protopodite with the ventral integument and interior supports
somewhat as the limbs of Apus and Limulus are attached to the body.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 383

Fic. 15. (5) Neolenus serratus. This is a reproduction of a photograph
of a portion of specimen No. 58580 illustrated by Walcott (1918, pl. 18) by

‘

a retouched photograph in which the coxopodites were too much “ restored”
by the artist. I succeeded recently in removing a little of the adhering dorsal
test of the specimen so as to give a better view of the coxopodites of three
of the limbs A, B and C (figure 15). These, as well as the posterior coxop-
odite D, show the notch of Raymond to be at the junction of the coxopodite
(1) and basipodite (2), also that the coxopodite (1) is in a natural position
in relation to the basipodite (2) and not reversed as assumed by Raymond
in his restorations of Neolenus (figures 7 and 8, pages 30, 31). The line
of the union of the ends of the joints of the endopodite and the distal end
of the coxopodite are usually very distinct when seen by reflected light, but it
is impossible to get all details in any one photograph as may be seen by com-
paring the coxopodite D of figure 15 with D of figure 2, plate o1.
A, B,C,D. Coxopodites of the four posterior limbs of the thorax.

I = coxopodite. 5 =carpopodite.
2= basipodite. - 6= propodite. —
3 = ischiopodite. 7 = dactylopodite.

4 = meropodite.

384 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

I have not used the term appendifer proposed by Raymond (p. 20)
as it does not appear to be the process to which the coxopodite of the
ventral limb articulated as he supposed. In fact there are two pro-
cesses, the one beneath the dorsal furrow at the union of the meso-
tergite and pleurotergite, and the usually more prominent one on the
ventral crest of the fold formed where the articular extension of the
mesotergite arches over to unite with the mesotergite (see figs. I, 3,
4, 5, of plate 102) ; this latter process may be called the mesotergite
process, and the one beneath the dorsal furrow the axial process.
I have not seen any evidence that either process extended down to
or through the ventral integument. They appear to have been points
of attachment for the internal muscles and the axial process afforded

Fic. 16—Ceraurus pleurexanthemus Green. Diagrammatic outline of a
transverse section of thorax that cuts across the deepest part of the ventral
fold of the anterior articular extension of the mesotergite. A section a
little in advance or back of this would not touch the lateral downward ex-
tensions of the fold a. a. or the low processes on the latter at x. x. The axial
processes a. p. are on the anterior margin of the mesotergite at its union
with the pleurotergite p. t. The spinous extension of the pleurotergite is
lettered p. s. and the mesotergite m, t.

The relations of the dorsal test and its ventral processes to the ventral
membrane and appendages are shown by the dotted outlines. v. m.—=ventral
membrane. cx.—=coxopodite.

a strong base for the muscles connecting the coxopodite of the ven-
tral limb to the dorsal test. The mesotergite process was not as
favorably situated and not as firmly supported as the axial process
to serve as a base for the muscles of the ventral limb. A diagramma-
tic outline of the dorsal test and the two processes that is based on
figure 4, plate 102 is here inserted as text figure 16. This illustrates
at a. p. the axial process and at x. the mesotergite process, formed
by the downward extension of the sharp fold of the anterior exten-
sion of the mesotergite as an articular process upon which the pos-
terior reflexed margin of the mesotergite rests both when the thorax
of the trilobite is straightened out and when it is enrolled. An out-
line of this structure is shown by figures 3 and 4, plate 96.

That many transverse and longitudinal sections of the thorax of
Calymene and Ceraurus show a narrow attachment between the cox-

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 385

opodite and the ventral integument indicates that the coxopodite as
well as its elongate connection with the ventral integument was when
in a natural position slightly oblique to the longitudinal axis of the
trilobite ; this causes the peculiar subtriangular sections of the cox-
opodite and the narrow point of contact between it and the ventral
integument. See figures 6 and 17, plate 95; figure 9, plate 99. A
few slides have cut across the longitudinal line of the coxopodite
and given such sections as those represented by figures I, 3, 4, 6, I1
and 15, plate 26, Walcott 1918. Of these, figure 11 (figure 6, plate
IOI of these notes) and figure 4, give the best longitudinal sections
but none show clearly the point of contact of the coxopodite and the
ventral integument, although it is suggested in figures 3, 4, 5 and 11,
plate 26, 1918.

The ventral surface of the test of the thorax of Cerawrus is illus-
trated by figure 4, plate 102. Without such an illustration it would
be exceedingly difficult to interpret the processes cut across in both
Ceraurus and Calymene. Figure 5 of plate 102 also indicates the
presence of strong points of attachment for muscles on the ventral
side within the dorsal furrow ridge and on the axial process.

It is highly probable that the dorsal margin of the coxopodite,
where the muscles passed through, was closely set into the edges of
the elongate opening for the passage of muscles through the ventral
integument, very much as in Limulus.

The genera Neolenus and Isotelus especially having almost no pro-
cesses beneath the mesotergite, the muscles must have been attached
directly to the dorsal test as in Limulus, and like the latter there must
have been quite a distance between the ventral integument and the
dorsal test that was largely filled in with muscles and the internal
organs of the body. It is difficult to conceive of any kind of a direct
joint between the proximal joint of the ventral limbs and the dorsal
test.

On the basis of the above data and the known method of attach-
ment of the limbs of Limulus, I venture to indicate the approximate
position of the muscles that held the coxopodite of the limb of Neo-
lenus in position and made it a strong, effective ambulatory leg (text

figure 13, p. 373). This form of attachment to the ventral surface
of the dorsal test, and in a less degree to the ventral integument,
would give a strong fulcrum and the necessary firmness to enable
the trilobite to use its endopodite as a walking leg and to push itself
along on the surface of soft sand and mud, and to force the front of
its cephalon into soft sediment when in search of food. Raymond
mentions “the prowling of trilobites” around in mud in search of

386 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

prey (p. 103). That some species crawled over and pushed their
way into the mud and silt is beautifully shown by the records left
on the argillaceous shales and sandstones of the Upper Cambrian
(Walcott, 1918, plates 37-42). On many of these trails the imprint
of the long coxopodites and endopodites is finely preserved (idem,
plate 38, figures 3-6). It is an interesting coincidence that trilobite
tracks and trails are often the most abundant on surfaces where
annelid trails are most numerous (idem, plate 42, figure 3).

The processes beneath the mesotergite of Cryptolithus tessalatus
Green are beautifully shown in some of Dr. Beecher’s specimens ;
they are proportionally much larger than those of Calymene and
Ceraurus and must have given a strong support for the muscles of
the stout ventral limbs of this species.

Position of the limbs in life—wNeolenus serratus had a thin test,
but when it is compared with the test of the king crab (Limulus) it
has about the same thickness in specimens of the same approximate
size. The test of the axial and pleural lobes of Neolenus was rein-
forced by rounded ridges and local increases in thickness that gave
it strength and, when attached to the ventral integument by muscles,
a rigidity that would permit of relatively great strain being applied
to it without flexing or breaking. With the muscles of the coxopo-
dite of the limbs of Neolenus extending through the ventral integu-
ment to the strong axial process and its base, the limb had a firm base
of support and the animal could use its legs (endopodite and long
coxopodite) to walk clear of the surface or push its way through the
surface of soft mud or sand in search of food, or sink and emerge
from it very much as Limulus does. Young specimens of Limulus
with the most delicate test manage to push themselves into mud and
sand so as to be nearly concealed from view, and from the study of
the tracks and trails I have referred to as of trilobitic origin, it seems
very probable that Neolenus and trilobites of a similar form had
the same habits.

The position of the flat coxopodites and the flattened joints of the
endopodites of Neolenus was probably nearly vertical with a slight
backward slant ; this is the position of the legs in Limulus and in the
closely arranged limbs of Apus, and with a relatively slow moving,
usually creeping, animal like Neolenus, Isotelus and allied forms,
such an arrangement would not materially affect their movements by
causing resistance in passing through the water when swimming.
The section of the coxopodite and proximal joints of the endopodite
of Neolenus is broad at the top, with deep, nearly straight, sides
and a slightly rounded ventral edge; this gave great strength and

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 387

kept the flat-lying shafts and fimbriz of the exopodites from drift-
ing down between the endopodites.

In considering the position of the appendages in life, one must always remem-
ber one great outstanding feature of trilobites, the thinness and flexibility of
the ventral membrane. The appendages were not inserted in any rigid test
but were held only by muscular and connective tissue. Hence we must pre-
mise for them great freedom of motion, and also relatively little power. The
rigid appendifers, and the supporting apodemes discovered by Beecher, supplied
fulcra against which they could push but their attachment to these was rather
loose. (Raymond, p. 74)

Ventral integument—Dr. Raymond (p. 50) refers to the ventral
membrane of Ceraurus and Calymene, but does not discuss the work
of Beecher* on the ventral integument of trilobites in which he
describes five oblique and transverse thickenings on the mesosternites
and homologizes them with apodemal structures of other crustacea,
and suggests that they afforded points of attachment for the ventral
muscles. If we consider the transverse arches in the ventral integu-
ment and the transverse thickening on them, it becomes apparent that
the ventral integument of the axial lobe was much stronger than it
is usually considered to be, and that it gave a firm base of support
and the opportunity for a close articulation of the coxopodites of the
ventral limbs, which were controlled by strong muscles passing from
the coxopodite through the ventral integument to the ventral surface
of the mesotergite and the axial process. A section of the ventral
integument with the thickened sternites is illustrated by figure 4, plate
101 and figure 1, plate 105.

Notes on individual specimens of Neolenus—Dr. Raymond has
given at length the results of his study of six of the best preserved
specimens of Neolenus that have more or less of the ventral appen-
dages preserved. I am in accord with most of his conclusions, but
will mention a few points where there is a slightly different point of
view.

SPECIMEN NO. 58589 (P. 24)*

Smithsonian Misc. Coll., Vol. 67, 1918, pl. 18, fig. 1; pl. 20, fig. 1; pl. or, fig. 2;
text fig. 15

This is the specimen in which Raymond discovered the “ articular

socket ” on the coxopodite. I have spoken of this (ante p. 381)

as his interpretation reverses the natural position of the dorsal and

*Amer. Jour. Sci., Vol. 13, 1902, pp. 165-174, pls. 4-5.
* The specimen numbers refers to the catalogue number in the records of
the U. S. National Museum, and the page reference to the Raymond Memoir.

388 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

ventral margins of the coxopodites, although the sketch (fig. 2, p.
24) shows them in their correct position in relation to the endopodite.
Since Raymond studied this specimen I have removed a fragment of
the dorsal test covering a portion of the coxopodites of the two an-
terior to those from which he made his sketch, and am now reproduc-
ing them as text figure 15 (p. 383) of these notes. A photograph of
three of the four coxopodites and attached endopodites is illustrated
by figure 2, plate 91, where on coxopodite D the proximal and ven-
tral spines are shown; also see figure 2, plate 93, for relation of
coxopodites and the endopodites. I think Raymond is correct in
interpreting the small epipodite of Walcott as probably the terminal
portion of an exopodite as I have already mentioned (ante p. 369).

If I understand the position of the “notch” that Raymond men-
tions as occurring on the coxopodite (our text figure 15 and figure 2
of plate 91), his measurement of the length of the coxopodite is
I.5 mm. too long, as the union of the coxopodite and basipodite was
at the notch and not r.5 mm. out from it.

SPECIMEN NO. 65514 (P. 26)
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 10, figs. 1-3

This is the specimen mentioned by Walcott (1918, p. 185, descrip-
tion of figure 3) as having two large epipodites. There are no epipo-
dites shown on it or in the figures of it, nor is it mentioned in the
text. I must have, as Raymond suggests, considered the ends of
the exopodites as the ends of the epipodites; this occurred when
writing the description of the plate figures.

SPECIMEN NO. 65519 (P. 27)
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 21, fig. 6

The exopodites of this specimen may be in a natural position but
there is no certainty of it, as the fragments of the endopodites
beneath the cephalon have been crowded forward and very much
displaced.

SPECIMEN NO. 65520 (P. 27)
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 22, fig. 1

Raymond mentions the “low rounded appendifers at the anterior
angle of each axial tergite.” A close inspection and the study of
other specimens in which the slender axial processes are preserved,
indicates that the latter have been broken off from all of the down-
ward projecting rounded bases situated on the ventral surface of

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 389

the mesotergites of this specimen at their anterior margin and
directly beneath the dorsal furrow. A low rounded ridge crosses
each mesotergite at its point of union with the pleural extension of
the segment, and an interior oblique ridge, corresponding to the
pleural groove of the dorsal surface, merges into the base of the
axial process, as does the rounded transverse ridge on the anterior
‘margin of the axial segment, thus giving a strong rigid support to
the base of attachment of the muscles extending from the coxopodite
of the ventral limbs to the axial process of the dorsal test and the
immediately adjoining surface of the mesotergite. The axial pro-
cess is slender and slightly inclined into the axial lobe but not as
much so as that of Ceraurus; it is as Raymond states, more rounded
in the pygidium of this specimen but this is probably owing to the
condition of preservation of this particular specimen.

The exopodites on the right side have been very much compressed
and all bent forward and crowded to the right. Walcott considered
that the distal ends of three epipodites projected from beneath the
exopodite on the right side, but this is doubtful, and I accept Ray-
mond’s view that they are probably the distal joints of three of the
exopodites.

SPECIMEN NO. 65515 (P. 28)

Smithsonian Misc. Coll., Vol. 67, 1918, pl. 20, figs. 3, 4; pl. 92, fig. 1, 2, 3, 3a, 4

The appendages of this specimen have been described and discussed
by Messrs. Ulrich, Ruedemann, and Bassler (ante pp. 366-368), and
I have agreed to their opinion that the so-called exites of Walcott
are not what I interpreted them to be. This is also the view of Ray-
mond, and he also eliminates the epipodites, considering them to be
merely exopodites without the fimbriz. The specimen is a difficult
one to photograph and to study, but on our plate 92, figures 1, 3,
3a, the attempt is made to reproduce the epipodites as photographed,
also for comparison the exopodites of specimen No. 65521. It is
unfortunate that Raymond did not make photographs of this and
other critical specimens and reproduce them, as Walcott’s figures of
1918 are nearly all badly reproduced. They should have been origi-
nally reproduced by the photogravure or similar process, but the war
time cost was prohibititive. The exites of Walcott (1918, plate 20,
figures 3, 4) appear to be the coxopodites of three of the ventral limbs,
the anterior of which has attached to it the basipodite ; the coxopo-
dites have been shortened and compressed to a thin film.

390 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

SPECIMEN NO. 65513 (P. 30)
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 16, figs. 1, 2

The limbs, coxopodites and endopodites of this specimen all appear
to have been crowded over from the left to the right side so as to be
in reverse of their natural position; two of the legs are above and
the two posterior beneath the exopodites. Whether they are “ cepha-
lic legs ” as stated by Walcott (1918, description of fig. 1, plate 16)
or thoracic appendages, cannot be determined. The displacement is
not unlike that of the appendages of specimen No. 65514, as shown
in the upper part of figure 3, plate 19, Walcott 1918.

There are a few other specimens worthy of notice as my observa-
tions in the paper of 1918 are too general to be of service in a review
of the structure of the appendages of Neolenus.

SPECIMEN NO. 58588
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 15, fig. 1; pl. 17, fig.3; pl. 91, fig. 1;
pl. 93, figs. 1, 2

This slab, with its two fine trilobites preserving both thoracic and
pygidial appendages, is of great interest. The upper one of the two
specimens shown on plate 15 (1918) is the matrix, but our figure 1,
plate 91, is a photograph of the trilobite itself with ventral appen-
dages projecting from beneath or exposed by the exfoliation of the
dorsal test.

Only a few traces of the exopodites remain and in these the fim-
brize are matted and rolled together in an indistinguishable, fibrous,
cord-like appendage on the right side and widely but faintly distri-
buted over the surface on the left side. The coxopodites and endo-
podites on the right side have been displaced and pushed outward
and slightly backward so as to bring the proximal end of the coxopo-
dite almost beneath the dorsal furrow; only a fragment of an endopo-
dite projects from beneath the left side. The backward displacement
of the appendages has brought eight of the legs opposite the pygi-
dium, of which the five posterior belong with the pygidium. The
sixth and seventh thoracic segments have been crowded into each
other with the result that of the limb opposite the seventh axial seg-
ment of the thorax, only the broad shaft of the exopodite is partly
preserved, the endopodite having been either torn away or pressed
deep into the sediment and lost to view. Counting this lost leg, the
three thoracic legs opposite the pygidium, and three of those oppo-
site the thorax, we have seven thoracic legs, or one for each segment.
There is a leg opposite both the first and second axial thoracic seg-

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 391

ments and the occipital segment of the cephalon, and one in advance
of it, the proximal end of the coxopodite of which touches the dorsal
furrow beside the glabella a little in advance of the occipital segment.
The total is sixteen endopodites or legs, or one for each segment of
the pygidium and thorax, and four for the cephalon, a fifth pair of
cephalic appendages being represented by the long slender anten-
nules. This is the only specimen thus far found of Neolenus serratus
that has as large a number of the ventral limbs so nearly in their
natural position. The fact that the ventral integument and limbs
have been squeezed out and shifted to the right and slightly back
from their natural position indicates that the muscles holding the
appendages and integument in position had sloughed off under pres-
sure; the marvel of it is that the coxopodites and endopodites held
together so well. ;

After studying the specimen I found that the coxopodites and the
proximal joints of the endopodite were in echelon with the ventral
margin of each limb passing beneath the anterior dorsal margin of
the next posterior limb. I then began to remove the covering
anterior margin of some of the limbs so as to expose the ventral
margin of the next anterior limb; this resulted in bringing into view
several coxopodites and basipodites with their spinose ventral side,
and what was of greater interest, the fact that the spinose margin of
the coxopodite in undisturbed complete limbs was on the ventral side
as in the basipodite and other joints of the endopodite, thus fully
corroborating the evidence of specimen No. 58589, represented by
our text figure 15 (see plate 91, figure 2). There is not any evidence
of an “articular socket ’’ on any of the coxopodites of specimen No.
58588, but the supposed “ notch” of Raymond occurs on the ventral
margin of several limbs at the union of the coxopodite and endopo-
dite. Two of the cephalic limbs preserve the six joints of the
endopodite and the coxopodite (figure 1, plate 93) in their natural
relation to each other ; the coxopodite is slightly shorter than that of
the thoracic limb, and the entire limb is slightly shorter and smaller
as indicated by the following measurements in millimeters.

Cox. Bas. | Ischi.}| Mer. | Carp. | Pro. |Dactyl.| Totat

Cephalic limb (2d)..| 8. | 4.5 | 4. | 4. | 4. | 2.75 |2. | 20.25
Dhoracic) th). 2... Oy Bes S75 3375 4: ays Bais A BOS

Pygidiah= (2d)... 2c: Asean lame me || 2anenreercr inooarial T 7s: TO. 7e 1.

392 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The ischiopodite and meropodite of the pygidial limb may have
been shortened by compression and the carpopodite lengthened a
little, but in all the limbs there is always a possibility of a slight dis-
tortion of the joints by compression; as a whole, however, they
retain their form and proportions in a surprisingly accurate manner.

The enlarged figures on plate 93 bring out in fine detail the endopo-
dites of Neolenus.

SPECIMEN NO. 57656
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 17, fig. 1

In the description of figure 1, plate 17, it is said that the caudal
rami have been dragged backward, pulling with them a portion of
the under edge of the body cavity. While this may be correct in
part, the edge of the supposed body cavity or ventral integument is
probably a displaced coxopodite with four joints of the endopodite
on the right side and a fragment of a coxopodite with a joint of the
endopodite on the left side.

SPECIMEN NO. 65521
Smithsonian Misc. Coll., Vol. 67, 1918, pl. 23, fig. 1

This is the ventral side of the test with the limbs partially pre-
served on the right side so as to show the ventral side of the outer
portion of a number of the exopodites and a few of the endopodites.
Walcott (1918, description of figure 1, plate 23) considered that the
distal lobes of some of the larger epipodites were preserved, but I
now agree with Raymond that there is not good evidence for this,
and that the distal lobes are those of exopodites. The.anterior exo-
podites on this specimen have their fimbriz finely preserved, as is
shown by figure 5, plate 92, of these notes.

Restoration of ventral surface of Neolenus—The theoretical
transverse section by Raymond of a thoracic segment and appendages
(fig. 7, p. 30) has the coxopodite of the limb articulating with the
downward projecting axial process (appendifer). The spine-bear-
ing ventral side and curved proximal end of the coxopodite is repre-
sented in a dorsal position, which reverses the position of the coxo-
podite in specimen No. 58589 (our text figure 15, and figure 2, plate
91) both in relation to the dorsal test and the joints of the endopodite.
In the Raymond restoration of the ventral surface (figure 8, p. 31)
the coxopodites of the cephalic region are represented with the
spinose ventral side sloping downward and forward with the shaft
of the exopodite attached to the ventral side of the endopodite, as

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 393

in figure 7, or, as I interpret the sketches, the coxopodite is drawn
in its normal position beneath the cephalon in figure 8, and upside
down in figure 7.

The restoration of the ventral surface of Neolenus by Raymond
is most effective, as it shows the broad side of the coxopodite and
endopodite, it being understood that both are in an unnatural posi-
tion. The exopodites are diagrammatic but with their very deep
(broad in the figure) proximal end joining the coxopodite, those of
the thorax and pygidium must be in an artificial position. My impres-
sion is that the proximal end of the exopodite was a narrow rounded
shaft as in our figures 13 and 14, pages 373, 375; for if it were flat
and as deep as Raymond shows it, and attached to the deep, flat basipo-
dite, it would be impossible for the exopodite with its flat, broad shaft
and long fimbriz to lie flat or horizontal above the endopodites with-
out breaking away from the proximal end of the basipodite. If, on
the contrary, it was attached to the limb in about the same manner
as the exopodite of the first thoracic limb of Anaspides tasmanie
G. M. Thomson (Walcott, 1918, plate 35, figure 2) it would have
had the position and flexibility essential to its functioning effectively.

The position of the coxopodites in figure 8, page 31, is somewhat
puzzling, as those of the cephalon are evidently intended to show the
spiniferous margin as ventral and sloping forward, while those of
the thorax and pygidium suggest that the spiniferous margin is
dorsal and projecting forward. This position is also suggested by
the position of the outline of the “articular socket” on the anterior
margin near the distal end of the coxopodite.

Attention should be called here to the position of the basal joints
of the thoracic limbs of Apus (Walcott 1918, plate 36, figure 4),
which slope forward when viewed from the ventral side and have
the spines on the ventral side and proximal end. I do not recall a
crustacean limb that has a series of sharp spines on the dorsal side
of the coxopodite or endopodite.

Raymond has inserted a metastoma and crowded the two anterior
cephalic appendages against the posterior end of the hypostoma;
this may be correct but as long as we have no evidence in Neolenus
to base it upon it may be misleading.

In my restoration, plate 94, I have omitted the small epipodites
and exites of the restoration of 1918 (plate 31), brought the inner
ends of the gnathites of the cephalic limbs closer together and made
a single round anal opening as the double opening of the 1918
restoration was based on a specimen (No. 58588) that a recent
photograph shows to have been imperfect at that place. I have been

394 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

misled a number of times by the effect produced by the direction
from which the light strikes this specimen and also others when too
hastily studied. ;

NOTES ON CERAURUS, CALYMENE, AND TRIARTHRUS BECKI
Illustrated on pls. ot, 95-103

Translucent sections cut from both Ceraurus pleurexanthemus and
Calymene senaria show the alimentary canal, what may have been
the heart and the main flexor muscles, and more or less of the out-
lines of the ventral integument and appendages.

The slides of Calymene will be arranged in their numerical order,
and those of Ceraurus will follow. Most of the slides illustrated
are described but a few are so simple that they are referred to only
in the description of the figures on the plates or in the general text.

Unless otherwise mentioned all the slides are in the collection of
the Museum of Comparative Zoology, Cambridge, Massachusetts.

CALYMENE SENARIA Conrad

Slide No. 5, M. C. Z. (plate 98, figure 6). Transverse section of a
partially enrolled Calymene cutting an anterior segment of the thorax
and diagonally through the cephalic appendages and the hypostoma ;
fragments of the slender epipodites occur on both sides above the
oblique sections of the endopodites; some of the latter appear to
indicate that one of the joints was hollow. There is a section of a
small narrow cephalic limb just above the hypostoma on the right
side and above are the sections of two large coxopodites, one of
which on the left side has several obscure joints that are filled with
small elongate oval-like bodies; the latter also occur scattered in
clusters in the calcite and appear similar to those illustrated by
figure 10, plate 98.

Slide No. 6, M. C. Z. (plate 101, figure 6). Transverse section of
the cephalon of Calymene. This section is in some respects one of
the best of the cephalic appendages of Calymene. It cuts across two
pair of slender, short coxopodites that were presumably anterior
and corresponding in position to the two small anterior cephalic
limbs of figures 2 and 3, plate 101. The large upper pair of coxopo-
dites appear to have been attached to the ventral surface (integu-
ment) near their proximal end; this is also suggested by slides No.
38 and 51 (Walcott 1918, plate 26, figures 6 and 9g), also figure 7,
plate 101.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 395

The grouping of the proximal ends of the limbs in slide No. 6,
also Nos. 38 and 51, strongly suggest oblique sections across the
mouth with some of the surrounding gnathites. Slide No. 6 was
illustrated by Walcott in 1881, plate 1, figure 6, and in 1918, plate 26,
figure II.

side No. 9, M..C: Z. (plate ror, figure 5; plate 95, figure 12).
Transverse section of the cephalon of Calymene and the anterior
mesotergite of the thorax cut so as to pass through the hypostoma,
a portion of the three anterior limbs of the cephalon and the large
coxopodite of the fourth pair of cephalic limbs; what may be a sec-
tion of a portion of a displaced alimentary canal occurs as a short
dark transverse crescent just beneath the mesotergite of the dorsal
test: this is much like the crescent in figure 13, plate 95. This slide
was imperfectly illustrated by Walcott, figure 9, plate 1, 1881. The
section of the alimentary canal was omitted in the drawing supposed
to represent a photograph of the slide.

Slide No. 20, M. C. Z. (plate 103, figure 14). Transverse section
of an enrolled Calymene. This is valuable for the information it
gives of the form of the cross section of the endopodites, which
appears to have been nearly circular ; the coxopodites were relatively
flat and deep in section as indicated by the sections of Calymene on
plate 101. See description of figure 14, plate 103, for further
remarks on slide No. 20.

This slide was illustrated by Walcott 1881, plate 2, figure ro.

Slide No. 28, M. C. Z. (plate 99, figure 5. Walcott 1881, plate 3,
figure 8. 1918, plate 27, figure 13). This is a section of one side
of an enrolled specimen of Calymene in which the filaments of three
or more exopodites have been cut across; a comparison should be
made with the fine fimbriated exopodites of figure 1, plate 96, in
order to better understand the exopodites of figure 5, plate 99, as the
latter do not show the spiral structure of the arm; the first of the
two right hand fimbriated appendages appears to have an elongate
oval section which is probably of secondary origin; the right hand
appendage may have been similar to the fimbriated appendage of
figure 8, plate 100.

This has long been a very difficult section to understand, but with
the discovery of the exopodite shown in figure 1, plate 96, the
fimbriated structure is more readily interpreted.

Slide No. 29, M. C. Z. (plate 99, figure 9) of Calymene is partly
represented by figures 8 and 9 of plate 97. The object of reproduc-
ing it entire is to show the transverse section of the longitudinally
undulating integument of the mesosternite and its relation to the

396 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

triangular sections of the coxopodites of the ventral thoracic limbs.
This is a portion of figure 9, plate 3, of Walcott 1881, which is a
drawing based on a photograph. A photograph of the entire sec-
tion was published in Walcott 1918, plate 27, figure 4.

Beecher in his memorable article * on the “ Ventral Integument of
Trilobites,”’ calls attention to this slide and considered that it indi-
cated folds and that in some sections cut by Walcott a normal apo-
deme was indicated (loc. cit. p. 169).

The spiral arms of the exopodites and slender epipodites of this
slide are illustrated by figures 8 and 9, plate 97. The shaft of the
exopodite is shown in figure 8, with the sections of two spiral arms
and beneath them the slender epipodites which are much better illus-
trated by figure 2 of this plate. In figure 9 there is a greater displace-
ment of the spiral arms. It was on the appearance of these two arms,
those of figure 10, plate 97, and those shown by figure 10, plate 3,
Walcott, 1881, that I ventured to restore the exopodite with a double
spiral. This is no longer tenable, as an exopodite with two arms of
the character we now know them to be, is not probable and the evi-
dence is insufficient. The slender arm next to the coxopodite may
be a section of a thin edge of two or three joints of an endopodite.
Walcott 1918, page 195, description of figure 4.

Slide No. 32, M. C. Z. (plate 97, figure 7. Walcott 1881, plate 4,
figure 4; 1918, plate 27, figure 5a). Longitudinal section of the
pleural lobe of a partially enrolled Calymene in which the spiral arms
of two of the exopodites have been pushed out of their natural posi-
tion, but fortunately they retain the proximal straight portion of the
arm and its union with the spiral portion; one of these (the lower
in figure 7) shows the proximal straight portion of the arm extended
along and connected with five sections of the spiral portion ; whether
this is always the case is uncertain but from a comparison with the
spiral arm of Cyamus scammoni Dall (see Walcott 1881, plate 4,
figure 9) it may be that the simple straight portion of the arm passes
directly into the spirals; further data is needed to determine just
how the two parts are joined. Slide 29 (plate 97, figure 8) is in
favor of the view clearly indicated.by figure 7.

Slide No. 34, M. C. Z. (plate 105, figures 1. and.2):) sheer
thick longitudinal slice of the axial lobe of Calymene. One side is
practically a duplicate of slide 35 (plate 1o1, figure 1) which was
cut from the same specimen but on the opposite side of the median
lobe. Both of these were a little to the right or left of the median

wAmMet JOU. Ci, Vola Lay LOO2s fea Za plas.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 397

line and do not cut the mesotergite process although they do pass
through the sharp fold where the anterior articular extension of the
mesotergite unites with the segment. (See Walcott 1881, plate 5,
figure 6). The opposite side of No. 34 has 18 well defined meso-
sternite segments with an interarticular membrane uniting them, three
faint posterior segments and traces of several coxopodites similar
to the short sections of them in slide 36 (figure 4, plate 101).

What appears to be a section of the alimentary canal (figure 2)
extends nearly the entire length of the thorax and pygidium; it is
situated directly above the ventral integument. Fragments of two
of three cephalic limbs occur beneath the cephalon. The mesoter-
gites of the dorsal test have been drawn apart a little which has
caused the ventral integument to pull away from the doublure of the
posterior end of the pygidium. This also shows in slide No. 35 which
was cut from the same specimen on the opposite side of the median
axis of the dorsal test.

Slide No. 35, M. C. Z. (plate ror, figure 1). This beautiful longi-
tudinal section of a partially enrolled Calymene cuts through the axial
lobe of the dorsal test a little inside of the dorsal furrow for the
anterior two-thirds or more of the length of the specimen, and then
a little inward nearer the center of the axis of the pygidium; the
ventral limbs are drawn forward and together so that they do not
correspond in position with the mesotergites ; there are 22 of the proxi-
mal portions of the limbs indicated, the anterior four of which are
referred to the cephalon, thirteen to the thorax, and five to the pygid-
ium. There were probably two or three more beneath the pygidium
of which no traces are preserved. The section on the opposite side of
the axial lobe of this trilobite (plate 105, figure 2) is almost identical
with this (Walcott 1881, plate 5, figure 3), and the median section of
the axial lobe (Walcott 1881, plate 5, figure 2; plate 105, figure 1)
shows the thickened mesosternites of the ventral integument.

Most of the proximal joints (coxopodites) of the ventral limbs
are joined to the ventral surface without any suggestion of inter-
vening joint, but three have what appears to be a small very short
joint between the coxopodite and the ventral surface; one of these
appears very much like the anterior limb of the pygidium of figure 9,
plate 103, where a short joint seems to be present between the coxo-
podite and the ventral integument.

Another interpretation of this is that the narrow connection
between the coxopodite and the ventral side of the animal is a cross
section of the ypace occupied by the muscles connecting the ventral
integument and the axial processes and mesotergite of the dorsal test.

398 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Slide No. 36, M. C. Z. (plate 101, figure 4; Walcott 1881, plate 5,
figure 4). Longitudinal section of Calymene a little oblique to the
median line of the axial lobe so as to cut the side of the hypostoma,
the proximal parts of two of the cephalic limbs (one of which has
been pulled out of place), six thoracic limbs, six of the thickened
mesosternites and fragments of several limbs on the opposite side
of the axial lobe from the cephalic and anterior thoracic limbs. This
section is instructive as it illustrates the strong mesosternite segments
and the direct contact of the coxopodites of the ventral thoracic
limbs with the segments ; slide 36 with slides Nos. 34 and 35, present
a fine illustration of sections of the coxopodites parallel to the axis
of the trilobite and of their relations-to the ventral integument.

Slide No. 38, M. C. Z. (plate 101, figure 7). Transverse section
through the cephalon, anterior thoracic segment of Calymene and
obliquely across the hypostoma. The portion of the cephalic limbs
cut across suggests the same structure as in slide No. 6, figure 6, plate
IOI, with one of the endopodites on the left side cut through so as
to give the narrow section of the joints and the one on the right the
broad section; the latter is not well shown in figure 7 as it too dark
to photograph well. A drawing published by Walcott in 1881, plate 1,
figure 8, shows the various parts more clearly. This drawing was
republished in connection with a photograph in 1918, plate 26, figures
9g, 10. The slender appendages on the left side in the drawing are
also too dark to photograph. The difference in the right and left
sides between the figures of 1918 and figure 6, plate 101, is owing to
the light being transmitted through different sides of the translucent
slide of rock.

Slide No. 45, M. C. Z. (plate 99, figure 2; plate 100, figure 3).
Oblique transverse section through the posterior part of the thorax
and the upper posterior margin of the cephalon of Calymene. The
filamentous appendages on the right side of figure 2, plate 99, are
enlarged in figure 3, plate 100, to show details of structure; the lobe
or base of the appendage is attached to the side of the mass filling
the visceral cavity beneath the axial lobe, but whether a short shaft
or arm connected the lobe with the coxopodite of one of the thoracic
limbs cannot be determined from this slide, but from the appearance
of the sections in figures 4, 6, 8, plate 100, it is probable that such
was the case. The manner of the insertion of the slender filaments
or tubes into the lobe is shown by figures 5, 6. In looking at this
slide it must be borne in mind that the trilobite was enrolled, that
five segments of the thorax are cut across and that the filaments or

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 399

tubes are long, relatively strong and do not resemble the filaments
of the spiral arms of the exopodites.

This slide was illustrated by a drawing in Walcott 1881, plate 3,
figure 1, and again in 1918, plate 27, figure II.

Slide No. 53, M. C. Z. Part of a transverse section through the
cephalon and an anterior thoracic segment of Calymene. ‘The sec-
tion cuts on the right side a mutilated coxopodite so as to give a
roughly triangular outline, and below it on the left two smaller joints
that may be portions of the coxopodites of two of the cephalic limbs ;
below and on the right there is a broadly jointed appendage that
from the direction of the upper joint evidently belonged with the
cephalic limbs, as it is within the cephalon and quite unlike the thor-
acic endopodites. This slide is illustrated by Walcott 1918, plate 26,
figure 12, by a print made from a plate that represents the appendages
in black with a white matrix, whereas the slide shows a black matrix
with the appendages in white calcite.

Slide No. 63, M. C. Z. (plate 91, figure 3; plate 99, figure 4).
Transverse thoracic section of Calymene, the most interesting fea-
ture of which is the displaced coxopodite of a ventral limb which has
a depression midway of the upper margin into which a projection
from the ventral surface projects forming the “ ball-and-socket ”’ joint
of Raymond (page 53, figure 15) ; the narrow sections of two addi-
tional pairs of coxopodites occur below and a number of slender
appendages on each side which may be drawn out spiral arms of
exopodites.

Slide No. 118, M. C. Z. (plate 95, figure 16). Transverse section
of Calymene with two dots in the space beneath the mesotergite of
the dorsal test that may represent the position of the dorsal flexor
muscles, and an arched, dark, line tentatively referred to as the heart.
This is the “ dorsal sheath ” of Raymond’s diagrammatic drawing of
this slide (figure 21, page 79).

‘Slide No. 153, M. C. Z. (plate 98, figure 5; plate 103, figure Io).
Raymond, page 70, figure 23. The descriptions of the figure 5, plate
98 and figure 10, plate 103, mention the principal features of this
slide of Calymene.

Slide No. 200, M. C. Z. (plate 103, figure 12). This slide of Caly-
mene is sufficiently described in the description of figure 12, plate 103.

Slide No. 211, M. C. Z. (plate 104, figures 1-3) is an oblique
transverse thoracic section of Ceraurus which has cut across the
articular fold of the mesotergite and the mesotergite process on the
right side (figure 1) (see plate 101, figures 1-8) ; and two distorted
coxopodites with several of the endopodites, exopodites and elongate

400 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

epipodites; the latter are best seen in figures 2 and 3 with their
elongate proximal joint which is very narrow at its proximal end
and broad at the distal end where the evenly jointed portion of the
epipodite unites with it; these proximal joints should be compared
with figures 1-4, 6, plate 97. A portion of a spinose ventral margin
of one of the joints of the endopodite is seen in the lower right
hand corner of figure 2. The light colored flocculent parts in figures 2
and 3 result from the strong light passing through very thin parts of
the slide.

CERAURUS PLEUREXANTHEMUS Green

_. Slide No. 13, M. C. Z. (plate 95, figure 6). Transverse thoracic
section of Ceraurus showing what appears to be a partially com-
pressed alimentary canal, an oblique triangular section of a coxopo-
dite of a ventral limb on the right side, with fragments of an endopo-
dite, and on the left side a distorted endopodite. Sections of slightly
undulating ribbon-like appendages that may be portions of epipodites
occur on both sides beneath the pleurotergites. This slide was illus-
trated by Walcott 1918, plate 26, figure 14.

Slide No. 16, M. C. Z. (plate 102, figure 10). Longitudinal sec-
tion of Ceraurus cutting the side of the axial lobe of the dorsal test
so as to section the mesotergite process of the articular fold, which
gives two small rounded subtriangular outlines similar to those of
figure 2, plate 102. When cut more obliquely the section of the pro-
cesses are more elongate as in figures 6, 8, 9. Another interesting
feature of slide No. 16 is the section of a long coxopodite of a thoracic
limb with its narrow attachment to the ventral surface of the body
and broad proximal end. The joints of the limb are undoubtedly
distorted and merged so as to lose their individuality. This section
was illustrated by Walcott 1881, plate 2, figure 16.

Slide No. 18, M. C. Z. (plate 103, figure 9). This is an instructive
longitudinal section of Ceraurus in which the proximal portions of
the ventral limbs of the pygidium are cut across; the sections of the
coxopodites appear to represent the narrow, flat section and not the
broad section seen in many transverse sections of the dorsal test.

An interesting and valuable feature of this slide are the clearly
defined mesosternites. The posterior one of the pygidium has what
appears to be a thin scale of the ventral integument adhering to it;
the second from the posterior end blends in with the base of the
ventral limb, and the third almost, but the fourth and fifth are
clearly defined and separated by a sharp line of demarcation which is
less well shown between the first, second and third sternites. The

NO. NOTES ON STRUCTURE OF NEOLENUS OI
4

mesotergites of the dorsal test were crowded apart so that the mud
of the matrix was forced under them and into the filling of the vis-
ceral cavity.

Particular attention is called to the short, narrow, transverse line
between the coxopodite of the anterior limb and the mesosternite as
it suggests a short joint, a feature also suggested by the next pos-
terior limb by it narrowing between the coxopodite and the mesoster-
nite. See also description of slide No. 35, page 397.

Slide No. 22, M. C. Z. (plate 99, figure 1; plate 100, figures 1, 2;
Waicott 1881, plate 3, figure 2; 1918, figure 12, plate 27). Slightly
oblique transverse section of the cephalon on the line of the eyes
and anterior portion of the thorax of a partially enrolled Ceraurus.
The cephalic limbs are grouped about the point that may have been
the mouth, very much as in slide No. 6 (plate ror, figure 6), but
the section is more oblique and cuts the deeper vertical section of
the coxopodites (gnathites), and the hypostoma is cut almost on the
plane of its marginal rim. There is a short transverse body near the
end of the hypostoma between the proximal ends of,the pair of
gnathites that strongly suggests that a metastoma has been cut across ;
it has been replaced by clouded calcite which makes it difficult to
photograph. The lower (in the photograph) left coxopodite has
been pushed inward and impaled on the mesotergite process.

The fimbriated appendages in the space on each side between the
axial lobe and the outer margin of the dorsal test must have been
lying nearly horizontally beneath the dorsal test and attached to
the coxopodites of either the posterior cephalic or anterior thoracic
limbs. These fimbriated lobes (epipodites) are illustrated on plate
100, figures 1 and 2, and described under the heading fimbriated
epipodites.

Slide No. 23, M. C. Z. (plate 100, figure 8; Walcott 1881, plate 3,
figure 3. 1918, plate 26, figures I and 2). This is a transverse sec-
tion of the cephalon and four segments of the thorax of Ceraurus;
the coxopodites of six pair of limbs have been cut across, the right
hand one of the posterior pair (Walcott 1918, plate 26, figures 1 and
2) showing a triangular section with a faint, slender, spiral arm of
an exopodite projecting from its outer proximal margin; on the
opposite side the coxopodite is badly distorted and broken up, but
connected with it there is a support to a narrow vertical lobe or plate
that carries numerous slender filaments, a photograph of which is
reproduced as figure 8, plate 100. There is also a row of somewhat
similar filaments next to the side of the cephalon and below the eye;
these filaments were probably attached to several lobes similar to

402 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 607

the one illustrated. The relations of the various parts mentioned is
shown by figure 2, plate 26, Walcott 1918.

Slide No. 27, M. C. Z. (plate 95, figure 1; plate 103, sade 4) is
a transverse section of a partially enrolled specimen of Ceraurus that
has one of the best preserved sections of a large alimentary canal of
a trilobite known to me. It is subcircular or broadly oval, with a
narrow, short midway extension on either side that may have been
an hepatic tube or the filled-in cavity of a flexor muscle ; it has within
it near the upper side a white, delicate convex or arching line that
is a section of the articular extension of the mesotergite that is
slightly out of its normal position, and above the canal and between
it and the dorsal test there is a dark arching line that is a little longer
than one-third the length of the arching mesotergite of the dorsal
test ; it may be a transverse section of the anterior incurving posterior
margin of the mesotergite. (See plate 96, figures 3, 4). Raymond
(p. 79, figures 21, 22) refers to these dark arched lines as dorsal
(figure 21) or abdominal (figure 22) sheaths.

Slide 27 also cuts across on the left side a palmate fringed appen-
dage (figure 5, plate 100) that is similar to the one illustrated by
Walcott (1881, plate 3, figure 2; 1918, plate 27, figure 12). Eight
filaments were attached along the outer fluted edge of a roughly
triangular palmate base. A fragment of a similar structure occurs
on the appendages of the two adjoining segments. The outlines of
two of the ventral segments (mesosternites) are shown as well as
the base of the ventral limbs.

Slide No. 80, M. C. Z. (plate 99, figure 6; plate 100, figure 6).
Transverse thoracic section of Ceraurus in which the coxopodite of
a distorted ventral limb is cut across, also the lobe of a fimbriated
epipodite of the type illustrated by figures 2, 4, 5 of plate Ico. On
the opposite side of the section a somewhat similar structure has been
pushed up against the side of the filling of the axial lobe of the dor-
sal test.

Raymond figures this slide as a diagrammatic drawing (page 49,
figure 12) to illustrate what he considered to be a section of an exopo-
dite and some of its “sete” in a longitudinal section.

Slide No. 109, M. C. Z. (plate 97, figure 2; plate 98, figure 1).
Transverse thoracic section of Cerawrus in which the coxopodites
of the ventral limbs were displaced and distorted and several joints
of the endopodites of five pairs cut across at different angles to the
axis of the limb; several appear to have been hollow and filled with
infiltered mud ; on the left side there are three slender jointed epipo-
dites (figure 2, plate 97), and on the right side fragments of slender

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 403

epipodites and exopodites. Some of the joints or endopodites on
the right side have slender spines attached to their lower inner mar-
gin, as seen in the section.

Slide No. 110, M. C. Z. (plate 95, figure 11). Oblique transverse
thoracic section of Ceraurus in which the alimentary canal has been
compressed and the ventral surface pushed up beneath the mesoter-
gite of the dorsal test carrying the oblique sections of the ventral
coxopodites with it; sections of portions of the exopodites that sug-
gest spirals are cut across beneath the pleurosternite on the left side
and fragments of endopodites below the coxopodites.

Slide No. 111, M. C. Z. (plate 104, figure 4; Walcott 1881, plate 2,
figure 2; 1918, plate 27, figure 1). Transverse thoracic section of
Ceraurus showing an unusual section of an endopodite, with five
joints and faintly two distal joints that probably belong with the
others, although they may not, as a short space separates them ; above
the endopodite there is a fragment of a spiral exopodite, and above
this and between it and the ventral surface of the pleurotergite,
fragments of three slender epipodites. In Raymond’s interpreta-
tion of this slide he considered the lower slendér epipodite to be the
arm, and the cut across sections of the spiral of the arm of the coxopo-
dite beneath, the filaments of an exopodite. (Page 58, figure 18).

Slide No. 112, M. C. Z. (plate 95, figure 15). Transverse section
of the axial lobe of Ceraurus in which a dark narrow transverse
area in the white calcite suggests a greatly compressed alimentary
canal, or possibly but not probably, the heart, as indicated in figure
16 and 17; also a fimbriated appendage on the left side similar to
that in figure I.

Slide No. 114, M. C.Z. (plate 95, figure 19). Transverse thoracic
section of Ceraurus in which sections of the supposed dorsal flexor
muscles are represented by two large dark dots one on each side of
the axial lobe of the visceral area; one or two similar dots occur in
other sections (figures 16,17, 18). The two lower dots are supposed
to be sections of the mesotergite processes. A subtriangular sec-
tion of two coxopodites of the ventral limbs are indistinctly shown,
also what may have been the shaft of an exopodite on the left side
apparently attached to the coxopodite.

Slide No. 115, M. C. Z. (plate 95, figure 17). Transverse section
of Ceraurus cutting through the hypostoma and anterior portion of
the cephalon on the left side and the anterior thoracic mesotergite
of the thorax; the two small dark lateral dots in the axial lobe are
referred to the dorsal flexor muscles, and the larger dot below on
the right side to a section of a mesotergite process or a ventral flexor

404 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67 :

muscle; the dark arched line separated from the mesotergite by a
narrow strip of calcite may possibly represent the heart. On the
right side there is a triangular section of a coxopodite, and on the
left side portions of two of the cephalic limbs that have considerable
width. The upper fragment is probably a portion of a thoracic cox-
opodite. What may be the shaft of an exopodite occurs just beneath
the filling of the pleural space on the left side.

Slide No. 117, M. C. Z. (plate 95, figure 10). Transverse thoracic
section of Ceraurus. This section is of interest on account of the
position of what was probably the alimentary canal, which has been
distorted and crowded up against the mesotergite of the dorsal test.
The position of the mesotergite process on each side is indicated,
and in a general manner the base of the ventral limbs. Two down-
ward curving points near the median line of the ventral integument
suggest the proximal end of the coxopodites.

Slide No. 119, M. C. Z. (plate 95, figure 18). Transverse thoracic
section of Cerauwrus in which the position of two supposed dorsal
flexor muscles are represented by irregularly rounded dark spots that
are considered to have been holes left by the decomposition and
removal of the muscles, the holes being subsequently filled by the
infiltration of the silt forming the matrix. The spots in this slide
should be compared with similar spots in figure 19. The two lower
dark spots are supposed to be sections of the mesotergite processes.
A partly triangular section of a ventral coxopodite is preserved on
the left side, and 8 mm. to the left of the point of the coxopodite there
is a fragment of an endopodite which has a notch into which another
distorted fragment of an endopodite projects, thus forming a fine
illustration of the “ ball-and-socket” joint of the appendifer and
coxopodite as described by Raymond (page 54, figure 15, page 53),
except that the appendifer is not present and the socket is simply an
indentation in a fragment of joint of the endopodite.

Slide No. 120, M. C. Z. Ceraurus. See description of plate 98,
figure 4, page 442.

Slide No. 123, M. C. Z. (plate 102, figure 5). Transverse section
of three slightly displaced thoracic segments of Ceraurus the upper
one of which has on the right the thickened base of an axial pro-
cess, and inward from it the fold of the mesotergite process, and
below in the mass of calcite filling the space between the mesotergite
and the ventral integument two sections of the mesotergite process.
The lower segment has on the left side (in the figure) a knob-like
section of the axial process and inward from it a mesotergite process
on each side of the median line; the section cuts across the two meso-

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 405

tergite processes at such an angle as to give the effect of having cut
obliquely across a short tube; figures 1 and 3, plate 102, show sections
of this process cut at a different angle. In slide 123 (figure 5) the
fold of the mesotergite articular extension is clearly shown.

Slide No. 147, M. C. Z. (plate 101, figure 8). Transverse sec-
tion of an enrolled Ceraurus that is interesting on account of the
sections of the coxopodites of the ventral thoracic limbs.

Slide No. 168, M. C. Z. (plate 103, figure 7). Longitudinal sec-
tion of the cephalon, hypostoma and the anterior portion of the axial
lobe of the thorax of a partially enrolled Ceraurus. The proximal
ends of the cephalic limbs have been pushed in above the hypostoma
and very much distorted ; the thoracic limbs have been cut across at
the coxopodite at such angle as to show the point of attachment of
the shaft of the exopodite to the coxopodite in the three anterior
limbs and doubtfully in the fourth posterior limb; just where the
actual point of attachment to the coxopodite was is not revealed by
this slide.

Slide No. 169, M. C. Z. Ceraurus. (plate 102, figure 6). See
description of figure on plate 102, page 447.

Slide No. 174, M. C. Z. (plate 103, figure 6). Longitudinal sec-
tion of the cephalon and thorax of a partially enrolled Ceraurus
showing the proximal portion of two cephalic limbs and their posi-
tion in relation to the hypostoma. ‘The entire section is not illustrated
by figure 6 as the limbs are displaced and the fragmentary sections
of the joints are not instructive.

Slide No. 193, M. C. Z. (plate 102, figure 9). Longitudinal
section of a partially enrolled Ceraurus which cuts through the side
of the axial lobe within the dorsal furrow; above the hypostoma and
between it and the posterior margin of the cephalon, four thick, evi-
dently distorted, coxopodites have been cut across, and beneath the
thorax six or seven imperfect coxopodites ; the mesotergites of the
dorsal test have been drawn apart so that their anterior articular pro-
jections are almost free from contact with the posterior part of the
segment next in advance. A section of the fold of the articular pro-
jection occurs between the fourth and fifth segments and there are
five sections of the mesotergite process anterior to it; the anterior
section of the processes has apparently been pushed forward; a
sharp mud-filled break in the cephalon occurs in advance of the
posterior glabellar segment. The thick or broad sections of the two
anterior limbs above the hypostoma should be noted as they are quite
unlike the narrow anterior limbs of sections 15, 17, figures 2, 3, 5
and 6, plate rot.

406 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Slide No. 198, M. C. Z. (plate 103, figure 8). This is another
longitudinal section of Ceraurus in which the section of the cephalic
limbs above the hypostoma are broad and strong as in slide No. 193,
plate 102, figure 9. All the portions of the joints of the limbs
exposed appear to have been forced out of shape and all form lost
except that of a flexible tube stuffed with animal matter now replaced
by calcite. .

Slide No. 202, M. C. Z. (plate 95, figure 8). Transverse, slightly
oblique thoracic section of Ceraurus in which the supposed alimen-
tary canal has been compressed and forced below its normal posi-
tion ; on the left side the outline of the mesotergite process is unusu-
ally definite and may be compared with that in figure 10. The dorsal
test of this section is finely preserved and there is more of the cal-
cite representing the contents of the space between the pleurotergite
and the ventral integument than is usually seen.

Slide No. 204, M. C. Z. (plate 97, figure 3; plate 98, figure 7).
Transverse thoracic section of Ceraurus with subtriangular section _
of two large coxopodites, to the left one of which there is attached at
the upper left side a short arm that has a faintly outlined slender
prolongation that is presumably one of the slender epipodites; two
other similar objects occur, one above and one below the arm men-
tioned. On the opposite side there is an indication that a slender
arm was attached to the upper right side of the coxopodite and
extended beyond as a slender appendage, suggesting that it had two
or more joints (figure 3, plate 97) ; below this there is a slender
appendage with a strong proximal joint that appears to have been
undulating so as to give a section of an arm broken into short parts ;
a similar arm occurs below, also in figure 4, plate 97 (slide No. 208) ;
the strong proximal joint is also seen in figures I and 4. The relative
size of the coxopodites and the slender epipodites is well shown in
this slide.

Slide No. 205, M. C. Z. (plate 95, figure 2; plate 102, figure 3) is
a transverse thoracic section of Ceraurus. It has a transverse sec-
tion of the alimentary canal beneath the axial lobe; four black dots
on the right side nearly on the line of the dorsal furrow, and one a
little to the right that may represent the flexor muscles of the meso-
tergite process; oblique sections of the coxopodites of several thor-
acic limbs, and in the space beneath the pleural lobe traces of dis-
placed endopodites; the pair of lower coxopodites indicate their
approximate position in relation to each other when in a natural posi-
tion. A fine section of what may be a mesotergite process (appen-
difer) extends obliquely into the axial space at the lower right side

NOw 7 NOTES ON STRUCTURE OF NEOLENUS 407

of the mesotergite of the dorsal test (plate 102, figure 3). The sec-
tion is slightly oblique to the longitudinal axis of the trilobite, which
gives a peculiar appearance to the section of the test on the right side.

Slide No. 208, M. C. Z. (plate 97, figure 4; plate 98, figure 3)3
This transverse thoracic section of Ceraurus has a fine section of
one of the slender epipodites with a large proximal joint, also a
broken section of an undulating slender epipodite and below the latter
a distorted spiral arm of an exopodite; there is also the skeleton
outline of an endopodite with five or more joints, and the coxopodite.
An undulating ventral integument beneath the axial lobe is suggested
by the manner in which some calcite is crowded up against an irregu-
lar dark line of rock crossing from side to side. A portion of what
may have been the filling of the alimentary canal occurs a little
beneath the mesotergite of the dorsal test.

Slide No. 228, M. C. Z. (plate 95, figure 13). Transverse thoracic
section of axial lobe of Ceraurus in which the supposed alimentary
canal has been crowded up against the articular extension of a meso-
tergite of the dorsal test and taken the form of a crescent with a
very definite outline.

Slide No. 231, M. C. Z. (plate 102, figure 8). Slightly oblique,
longitudinal, thoracic section of Ceraurus cutting across several meso-
tergites of the dorsal test in such a manner as to show the three
right hand segments, the outline of an oblique section of the anterior
articular extension of the tergite and beneath on the left hand three
sections of the mesotergite process. Compare this with the other
figures on plate 102.

Slide No. 244, M. C. Z. (plate 95, figure 4; plate 102, figure 1).
This is a transverse section of a partially enrolled Ceraurus cutting
four thoracic segments nearly on the plane of the dorsal surface of
the pleural lobes of the test and one upturned (down in the figure)
segment beneath which there is a fine illustration of a section of the
alimentary canal. The sections of the fold at the union of the articu-
lar extension with the body of the mesotergites are exceptionally
good and serve to interpret the sections represented by figures 3, 6,
8, 9 and 10 of plate 102, and with figure 4, to visualize the mesoter-
gite process as a downward lateral extension of the fold at the base of
the anterior articular extension of the mesotergite.

Spiral branchie—These appear to have given Raymond more con-
cern than any other of my interpretations of the appendages exposed
by the sections cut through specimens of Calymene and Ceraurus.
I deeply sympathize with him as I found them most difficult to
visualize and interpret. The reason for my originally accepting the

408 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

‘‘ spiral’ interpretation is as follows: When thinning down trans-
verse and an occasional longitudinal section of Calymene and Ceraurus
with emery dust on a glass plate, I occasionally noticed a row» of
minute oval dots on the section. As the removal of the surface of
the slide progressed, the dots began to elongate transversely and more
or less obliquely (see figure 1, plate 96), then to narrow at the center,
and soon a double row of round dots appeared that indicated a cross
section of a spiral. Continuing the cutting the dots became elongated,
and soon reunited and narrowed to oval dots and finally disappeared,
as the removal of the surface cut deeper into the specimen. From
these progressive sections I inferred that coils of a more or less com-
pact spiral wire-like filament had been cut through.

Subsequently I found that by cutting across closely coiled spirals
of wire set in plaster (1918, plate 27, figures 10, Ioa@) most of the
spiral-like structure seen in the sections of Ceraurus was duplicated
in detail.

During the cutting of sections over a period of several winters,
this experience was repeated from time to time and sketches made
of the successive exposures of the apparent spiral structure, but I
could not preserve all the data found while grinding down the sections
as there were no facilities available to me for photographing opaque
sections.

I did not observe any branchial filaments attached to the spirals
cut or progressively worn through from side to side, but many fila- .
ments that were free or attached to others parts were cut both longi-
tudinally, obliquely, and transversely. The filaments were rarely
seen attached to any kind of a base, but occasionally they were as
shown by figure 12, plate 27 of the paper of 1918 (which is a draw-
ing from a photograph of a thin section) ; see also figures 11 and 13
on the same plate, though I did not associate these with the spirals.

I knew very well in 1918 that the spirals might possibly be.
explained as oblique sections of filaments such as occur on the exopo-
dites of Triarthrus or Neolenus, as had been suggested by authors, but
the conclusion that there was a spiral-like appendage independent of
the blade or arm with filaments attached to the proximal joint of the
limbs in Calymene and Ceraurus, was so firmly impressed on my
mind that I could not abandon it.

Raymond (pp. 48-50) assembles a formidable array of arguments
against the possibility of the presence of spiral exopodites, but after
reading them I was still unconvinced but realized that the presence
of a spiral-like structure in Calymene and Ceraurus was rendered

“NO. Fh NOTES ON STRUCTURE OF NEOLENUS 409

exceedingly doubtful to the general student and that it was relegated
to the class of disproved theories. As a last resort I decided to
make thin sections of a number of specimens of Calymene collected
by William P. Rust for the National Museum many years ago, and
a few of Ceraurus, all of which came from the locality and layer
of rock worked by Walcott prior to 1876. This was undertaken in
the hope that a section might be cut across on the plane of an elon-
gated arm of the exopodite and, if present, an attached fringe of
filaments. Spirals were found and a few stray unattached filaments,
but it was not until the next to the last slide of Calymene was rubbed
down thin that a series of undoubted spirals was seen in shadowy
outline ; a little reduction in the thickness of the slide and the spirals
became more distinct and a fringe of filaments was indicated; a
further reduction and the filaments extended back to the spirals and
joined them, and I had in my hand the evidence that I had searched
for from 1873 to 1879 and at intervals since. (See plate 96, figure
1). The arm of the exopodite of Calymene senaria as it appeared
in the section was clearly and unmistakably a spiral-like structure
with a filament attached to the side of several segments of the spiral ;
all the spiral phenomena I had observed in my early work are beauti-
fully shown in this slide by a series of round and elongated single
and double rows of dots, faint and distinct spiral structure, and what
was new, the mode of attachment of the filaments to the spiral arm.

Exopodtte of Calymene.—tThe slide referred to in the preceding
paragraph (U.S. National Museum, Catalogue No. 68379) is repre-
sented by figure 1, plate 96, and a restoration of a portion of the exo-
podite by text figures 17, 17a.

There are portions of nine exopodites cut across in the slide at a
more or less oblique angle to the axis of the arm and attached fila-
ments. The exopodites had been pushed back into the half enrolled
posterior portion of the trilobite and displaced so that they were
beneath the axial lobe with their longitudinal axes subparallel to the
axial lobe of the dorsal test. As seen in the section (figure 1, plate
96) the upper arm (1) is represented by a row of small round white
dots with a few oblique transverse segments on the left end, and.
transverse faint oblique lines that give a spiral appearance to the
section of the arm. The second exopodite (2) has about 26 obliquely
transverse segments and spiral structure indicated. The third
(3) exopodite has a distinct spiral with about 24 oblique segments ;
the spiral structure is more pronounced in the fourth (4) and the
30 segments are more strongly outlined and some are broader, but

410 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the spiral structure is preserved about midway of the length of the
arm; the fifth (5) exopodite has about 40 segments indicated and
the section shows 16 or more long slender filaments a number of
which are connected directly to the segments of the arm, but the
section does not cut. across the exact point of contact with the seg-

Fic. 17.—Diagrammatic outline of a dorsal view of a portion of a thoracic
exopodite of Calymene. 1-9=close coils of a spiral arm. 1-7—=bases (a)
of seven branchial tubes (b) attached to dorsal side of the coils of the spiral
arm. a= supporting base of branchial tube attached to spiral arm. b —=bran-
chial tube inserted in a at c. d=hollow interior of spiral arm of exopodite.

ments of the arm in a manner to clearly indicate the character of the
union betwen them; this is found in the sixth (6) exopodite which
has six filaments and portions of transverse spiral segments. The
cut is diagonally across the segments and brings into view the thick-
ened sheaths of three segments with the point of insertion of the

Fic. 17a.—Sectional view of diagrammatic outline of exopodite represented
by fig. 17. (Lettering the same.)

filament into the supporting sheath. The seventh, eighth and ninth.
exopodites expose only a few segments of the arm, and afford no
additional data on the structure of the exopodite.

My interpretation of the structure that when cut across gives a
spiral outline in the sections of the exopodites in this slide is graphi-
cally shown by text figures 17, 17a.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS A4II

The spirals seen in so many sections of Ceraurus and Calymene
result from cutting across rounded, narrow, oblique coils of a hol-
low, spiral arm of the exopodite to which the bases or sheaths of

Fic. 18—Photograph of several spirals formed of wire and flattened more
or less by compression. These spirals suggest the probable form of the spiral
arms of the exopodite of Calymene and Ceraurus:

long slender filaments (tubes) are attached ; each obliquely arranged
segment of the spiral is in vertical section, a portion of a spiral that
was more or less flattened on the dorsal and ventral sides; the fila-_

Fic. 19.—Diagrammatic outline of a dorsal view of a portion of the exopo-
dite of Triarthrus. a=three segments of the supporting arm. b=support-
ing bases of branchial tubes, two attached to each joint of the supporting arm.
¢=point of insertion of branchial tube into base a. d—=hollow interior of
arm of exopodite.

ments were attached to the posterior end of a base or sheath attached
to the dorsal side of the spiral coils of the arm; this is indicated by
exopodite numbered 5 of figure 1, plate 96, and more definitely by

i Ties b

Fic. 19a.—Sectional view of diagrammatic outline of transverse section of
exopodite represented by fig. I9. (Lettering the same.)

number 6, where the point of insertion of the slender filament is
shown as well as can be in a section; the dorsal position of the sheath
or base of the filaments is corroborated by the arm of the exopodite

412 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of Triarthrus becki, where it rests on and is attached to the dorsal
side of the segmented section of the arm (see plate 95, figures 20-23).

The relation of the exopodites to the endopodite and coxopodite
is not seen in slide No. 68379, but it is indicated by several sections
one of which is represented by figure 2, plate 26, figure 4, plate 27,
Walcott 1918 and plate 97, figure 8.

Exopodite of Ceraurus——Many sections of the spiral arm of the
exopodite of Ceraurus have been made since I began sectioning
specimens in 1873, but none of them showed the connection between
the spirals and the slender tubes or filaments, but the section of
Calymene described above gives the key to the structure and indi-
cates that the spirals of Ceraurus are sections of the arms of the
exopodites and have exactly the same structure as those of Caly-
mene, as may be seen by comparing the spirals of Calymene (figures
4,5, 5a) with those of Ceraurus (figures 3, 6, 8, 9, plate 27, Walcott
1918).

Structure of exopodite of Calymene and Ceraurus.—None of the
sections of either species clearly shows the proximal segment or shaft
of the arm of the exopodite, but several afford data from which we
may assume its character with a fair degree of certainty. Section 23
(M. C. Z.), Walcott 1918, plate 26, figure 2; sections 29, 30, 31 (M.
C. Z.), Walcott 1881, plate 3, figures 9, 10; plate 4, figure 3, of Caly-
mene; section 32 (M. C. Z.), Walcott 1881, plate 4, figure 4, of
Ceraurus, figures 7, 8, 9, 10, plate 97 all indicate a simple slender
elongate segment between the coxopodite and the obliquely trans-
verse hollow spiral segments of the filamentous portion of the arm;
fragments of the spiral portion of the arm are cut across in a num-
ber of sections but it was not until the restudy of the sections in
connection with these notes that I succeeded in getting satisfactory
photographs of the shaft and the connection between it and the
spiral of the arm of the exopodite. These are reproduced in figures 7
and 8, plate 97, and indicate that several turns of the spiral arm
were attached to the distal end of the shaft. The coil of the spiral
appears to have been quite close when the animal was alive, but
when subjected to the vicissitudes following death and entombment
in the soft sediment, the spiral was loosened and often drawn out as
illustrated by the spirals figured by Walcott in 1918, plate 27, figures
3-9, and on plate 97, figures 7-11 of these notes.

The elongate base of the filaments of the exopodite of Triarthrus
are oblique to the axis of the arm, and the structure was probably the
same in the exopodite of Calymene and Ceraurus.

NO 7 NOTES ON STRUCTURE OF NEOLENUS 413

The filaments of the exopodite of Calymene and Triarthrus are
very slender tubes and in section give a beautiful fringe of fimbriz
as shown by figure 13, plate 27, Walcott 1918, and figure 1, plate 96,
of this paper.

Arm No. 5 of figure 1, plate 96, of Calymene indicates that 39 or
40 segments have been cut across, and the proximal section exposed
is evidently not the first one, but from its position I presume that
there are not many more before the union with the shaft connecting
the spiral arm with the coxopodite, so we may assume that the arms
of the thoracic exopodites had between 35 and 40 segments (=coils
of the spiral arm).

As far as may be determined from the evidence afforded by many
sections of Calymene and Ceraurus cutting the arm of the exopodite,
it is very rarely that the layer of sheaths or supports of the filaments
(tubes) remained attached to the arm of the exopodite. The attach-
ment of the sheaths to the spiral arm must have been relatively deli-
cate and easily broken when the arms were displaced and the
branchial tubes dragged about by movement in the soft sediment in
which they were being embedded. This condition explains the
presence of so many of the strong spiral arms of the exopodites and
the absence of the supporting sheaths and the fringing tubes or
filaments.

In the case of Triarthrus becki the animal settled down quietly on
the surface of the mud and was not disturbed except by flattening
out under pressure of accumulating sediment, which process some-
times displaced the limbs by sliding them out from beneath
axial lobe ; usually the endopodite and exopodite retain their natural
position, being displaced only by the downward or upward pressure
of the outer ends of the thoracic pleurz or the margin of the pygi-
dium or cephalon.

Exopodite of Triarthrus—Raymond suggests that the spirals seen
in sections of Calymene and Ceraurus are the result of cutting (p. 50)
across the “sete” of the exopodite, but he does not refer to the
structure of the exopodite of Triarthrus in which there is a closely
jointed rounded arm of many segments upon the upper side of which
there is superimposed (plate 95, figures 20-23) diagonally and closely
arranged slender, convex supports or sheaths of long, slender, round
filaments similar to those cut across in Calymene (plate 96, figure 1).
This structure was illustrated by Walcott (1918, plate 20, figures 2,
2a and 11) but he did not then compare it with the exopodite of
Calymene and Ceraurus, as the connection between the fringing fila-
ments of the arm of the exopodite of Calymene and the associated

AI4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 67

spirals was unknown. There is no evidence that the same kind of
a jointed arm as that of the exopodite of Triarthrus was present in
the exopodite of Calymene and Ceraurus but that there was a sup-
porting spiral arm strengthened by the attached layer of sheaths of
the fringing filaments appears to be well established.

The dorsal side of the arm of the exopodites of Triarthrus is
finely illustrated by Beecher’s photographs as reproduced by Ray-
mond, plate III, figures 1, 5, 6; plate IV, figure 6, but none of them
appear to show the many jointed supporting arm, nor do I find a
reference to it by either Beecher or Raymond. It occurs on specimen
No. 221, illustrated by Raymond, plate 5, figure 5, but his reproduc-
tion is too poor to show it clearly. Compare this figure with that
on plate 95, figure 20 of this paper, as they appear to represent the
same view of the exopodite.

In nearly all specimens of Triarthrus showing the exopodites it is
the dorsal side that is exposed and the layer of basal sheaths of the
filamentous tubes is so closely attached to the jointed supporting arm
of the exopodite that the arm is entirely concealed from view except
when occasionally the long distal segment of the arm projects a little
beyond the distal end of the exopodite. It was only by a fortunate
find that I became aware of the existence of the arm in Triarthrus
and its relations to the sheath layer above it. The specimens showing
it may be described as follows.

Specimen No. 65523, U. S. N. M. (plate 95, figures 22, 23) of
Triarthrus has two of the jointed arm supports of the exopodite
lying above the endopodites; the posterior one has eleven closely
united joints, the length of each one of which is about 1.5 times as gréat
as its diameter and the distal end has a slight raised rim against which
the proximal end of the next joint impinges; the anterior arm has
seven or eight joints that taper gradually to a short slender terminal
joint. The arm with 11 joints has the bases or sheaths of 22 rounded
tubes or filaments just above its anterior side, which indicates that
there are about two tubes or filaments to each joint of the arm. The
layer of supporting diagonal tubes of the filaments or tubes of each
arm has been pressed forward so as to be almost clear of the jointed
arm support, only a few of the round filaments resting on its dorsal
side.

Specimen No. 65529, U. S. N. M. (plate 95, figure 20) shows three
exopodites which have been displaced and pushed along parallel to
the outer margin of the ventral surface of the dorsal test. The sup-
porting arm has been compressed so as to slightly distort the joints
and make them transversely a little oblique to the axis of the arm;

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 415

the series of bases of the tubes or filaments are also oblique in the
same manner as those undisturbed in specimen No. 65523. The long
exopodite of figure 20, plate 95, shows the ventral side of the sup-
porting arm and its anterior upper edge where the layer of bases of
the branchial tubes was attached to the arm.

Specimen No. 68387, U. S. N. M. (plate 95, figure 21) has two
flattened arms of thoracic exopodites entirely concealed except at the
distal end by the layer of obliquely aligned bases of the branchial
tubes; of the latter there are more than forty, about two-thirds as
long as that portion of the exopodite between the shaft at the proxi-
mal end and the round slender distal joint of the arm. The tubes are
very slender, more or less flexuous, and terminate in a rounded
blunt point; they may be compared with the branchial tubes of the
exopodite of the thoracic limbs of Marrella splendens.

Pygidial endopodites of Triarthrus—Raymond (p. 42) calls atten-
tion to the difference in interpretation of the development of the
endopodites of small pygidia by Beecher and Walcott, Beecher con-
sidering them true endopodites in the specimen studied by him (No.
222, plate IV, figure 5, of the Raymond memoir) and Walcott con-
sidering the possibility of their being the transverse segments of the
supporting arm of the exopodite (Walcott 1918, page 142, plate 29,
figures 4,5). Raymond states : “On careful examination, however,
the specimen shows, as Beecher indicated, a series of endopodites in
undisturbed condition (our plate 4, figure 5).”

A careful study of specimen 222 convinces me that Beecher and
Raymond are correct in their interpretation of that specimen, and
that the exopodite of specimen No. 65524, U. S. National Museum
(Walcott 1918, plate 29, figure 5) has an apparently identical struc-
BUTE:

When I spoke of Beecher’s interpretation I had in mind his figures
I and 3 of 1894 (Amer. Jour. Sci., Vol. 47, 1894, plate 7) and his
comparison with the larval endopodite of Apus (figure 4).

Anal plate—Raymond illustrates what he calls the anal plate
(figure 11, page 44, specimen No. 65525, U. S. N. M.) and states
that the hemispheric mound at the middle of the anterior half is
perforate for the opening of the posterior end of the alimentary canal.
I find an uneven, somewhat jagged, depression near the posterior cen-
tral part of the convex body of the “anal plate,” but it is not clear
that there is a perforation. Specimen No. 65524 (Walcott 1918,
plate 29, figures 4, 5) has a similar structure but the “ hemispheric
mound” is covered with minute granulations and a longitudinal
median depression extends the length of the convex portion; the

416 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

marginal spines on this specimen appear to be the proximal portion
of five of the pygidial limbs. The spines on specimen No. 65525
also appear susceptible of being interpreted as the coxopodites of
very minute pygidial limbs.

It may be well to consider that the so-called anal plate may be
the ventral integument of the posterior part of the pygidium which
has been squeezed out from beneath the pygidium bringing some of
the minute pygidial limbs along with it and that the dome may be
the cast of the posterior portion of the axial lobe of the pygidium
formed by the pressing of the ventral integument into it. More
specimens are needed in order to arrive at a final conclusion.

NOTES ON INDIVIDUAL SPECIMENS OF TRIARTHRUS
BECKI Green

Through the courtesy of Dr. Charles Schuchert of the Peabody
Museum, Yale University, I have had the opportunity of looking
over the type specimens of this species prepared and studied by Dr.
Charles E. Beecher and recently illustrated by Raymond from the
Beecher photographs. Some of the specimens have been photo-
graphed by Dr. A. J. Olmsted, chief photographer of the U. S.
National Museum, who has obtained very excellent results. The
specimens are excedingly difficult to photograph as the yellow pyrite
and black, often shiny, shale reflect the light badly and usually the
surface of the appendages is roughened by the finely botryoidal
structure of the pyrite. I should like to reproduce a number of the
photographs but that is impracticable in this paper. A few frag-
ments are illustrated on plate 104, figures 12-15. ;

Specimen No. 211 (plate 104, figure 15). This is a portion of the
specimen including the gnathites, the posterior portion of the hypos-
toma, the margin of which is broken away and a peculiar ribbed
surface between the inner ends of the gnathites that may be formed
by stout short spines attached to the inner end of the gnathites. No.
211 is illustrated by Raymond, plate II, figure 5.

Specimen No. 218 (plate 104, figure 13). This is a portion of the
photograph that includes two of the.posterior thoracic limbs that are
in a peculiar position. The coxopodite, basipodite, and ischiopodite
are turned up so as to show the thin ventral edge of the joints; the
meropodite is tipped over so as to show the broad side of the joint
which is nearly at right angles to the ischiopodite ; the carpopodite is
also lying on its side and is followed by the propodite and dactylopo-
dite. It appears evident that the first three joints of the limb retained
their natural position and the proximal four were bent back and are

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 417

flattened broadside on the shale. The exopodites have retained
their natural position on the dorsal side of the limb.

-Raymond’s interpretation of these limbs is shown by a diagram-
matic drawing (figure 43, page 157) in which he has introduced a
very short basipodite as the result of figuring the short ventral side
of the joint and not noting that the dorsal side of the joint has
slipped by and overlapped the ischiopodite.

Specimen No. 219 (plate 104, figure 14). This is a part of a pho-
tograph showing the apodemes very clearly. Raymond reproduces
a photograph by Beecher (plate IT, figure 6; plate IV, figure 4) which
does not show them as well as in the original photograph.

Specimen No. 222 (figures 12, 12a, plate 104). These photographs
are reproduced as the specimen shows the thin ventral edge of the
joints of the endopodite, also by changing the point of view the
flat anterior side of the joints. In figure 13 both the thin ventral,
edge of the three proximal joints of the limb are shown, also the
flat side of the two succeeding joints.

Raymond illustrates No. 222 on plate IV, figure 5.

FIMBRIATED EPIPODITES OF CALYMENE AND CERAURUS

In addition to the spiral filamentous exopodites, several sections
show a fringe of long rather strong fimbriz attached to a more or
less subtriangular base. The most striking examples are illustrated
by figures 1-6, plate 100, of this paper. Raymond has given an inter-
pretation of these in the restoration of the exopodite of Ceraurus
(plate XI) which is represented as relatively short and about one-
half the length of the endopodite ; it is fringed with strong expand-
ing filaments, the conception for which was probably derived from
slide No. 22, illustrated by Walcott by a somewhat diagrammatic
drawing in 1881, plate 3, figure 2, and 1918, plate 27, figure 12 and
now by figure 2, plate 100. Several other slides show a somewhat
similar structure; No. 21 (1918, plate 27, figure 11), No. 27 (Wal-
cott 1921, plate 100, figure 5), No. 112 (Walcott 1921, plate 100
figure 4). All of which are of Ceraurus except Nos. 27 and 112 of
Calymene. In each slide the supporting base of the fimbriz or fila-
ments is cut across at such an angle as to give a roughly subtriangular
outline with the filaments attached on the broad outside margin. In
slide No. 22 (plate 100, figure 2) the upper 12 filaments on the right
side appear to be attached to a base and the lower four are probably
the distal ends of filaments belonging to an adjoining base. In slide
45 (plate 100, figure 3) the filaments appear to belong to three bases ;
in slide No. 27 (plate 100, figure 5) they are attached to two, and in

418 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

slide 112 (plate 100, figure 4) to one base. In none of these slides is
there an indication of a long, broad arm or shaft of an exopodite
such as is drawn in Raymond’s restoration of Ceraurus (plate XI),
or the long, narrow shaft in Calymene (figure 16, page 55), but sev-
eral other slides appear to show sections of an elongate slender shaft,
No. 109 (plate 97, figure 2), No. 12 (Walcott 1918, plate 27, figure
1) ; slide No. 12 may have been the one from which Raymond drew
his figure 18, page 58, but which he refers to slide No. 111. The
latter slide has a long slender appendage apparently attached to the
section of the coxopodites beneath both the right and left pleural
lobes. None of the slender appendages of these slides appear to
have filaments attached to them, and several appear as though an
undulating or straight ribbon-like tube had been cut longitudinally or
slightly oblique to their axis and others are undoubtedly jointed;
some resemble sections that might have been cut from the long cylin-
drical filaments of the branchiz of Cyamuus diffusus Dall (Walcott
1918, plate 28, figure 10).

In my paper of 1918 (page 150) the fimbriated appendages were
considered to represent the epipodite of the ventral limbs, but Ray-
mond (pp. 48-50) considers that they represent a section across
the shaft of the exopodite with attached “ sete.’ The segmented
spiral character of the arm of the exopodite of Calymene now being
known, and the presence of a similar exopodite in Ceraurus being
inferred from the spiral-like section of the arms, although the fringe
of filaments has not been found attached to it, we have to interpret
the other fimbriated appendages independently of the exopodites, as
they do not appear to represent sections of the latter.

The exact form of the plate or body of this appendage cannot be
accurately determined by the sections, but all of those seen have a
roughly subtriangular section with a slender attachment to the coxo-
podite, or it may have been the basipodite as the two joints cannot
be separated in the sections showing the fimbriated appendages under
consideration. I am not convinced that the fimbriated appendages ~
are undoubtedly epipodites but I do think that they are not exopo-
dites. It has been suggested that they might be a modification of the
exopodite attached to the cephalic limbs; this may be, but in one
instance at least (figure 5, plate 100) they are clearly beneath a thor-
acic segment; in this section (No. 27, M. C. Z.) the slender arm of
an expodite is shown on the right side and a little of the spiral struc-
ture of the arm.

It is not at all probable that the spiral arm of the exopodite of
the thoracic limbs with its basal sheath and slender tubes would be

INO. 7 NOTES ON STRUCTURE OF NEOLENUS 419

replaced by such a structure as that shown by figures 1-6, plate 100.
There is nothing in common between them except the fringing fila-
ments.

The fringed epipodites of Calymene and Ceraurus (plate 100) are
not unlike the epipodites of some of the thoracic limbs of the
Euphausiacean Meganyctiphanes norvegica.. These epipodites are
referred to as branchia; they are formed of a short base attaching
them to the coxopodite of the thoracic limb and a transverse bar of
varying form to which are attached numerous slender tubular fila-
ments. Our figure 8, plate 100, may be compared with Dr. Calman’s
figure 141, B and C. The endopodite and exopodite of this species

Fic. 20.—Outline of diagrammatic restoration of a fimbriated epipodite of
Ceraurus based on figs. 1, 2 and 6, pl. 100.

are attached directly to the coxopodite. The epipodites hang freely
at the sides of the body and are not covered by the carapace as are
the podobranchiz of the Decapoda and the trilobite.

The long slender jointed epipodites have a superficial resemblance
to the branchiz of the Amphipod Paracyamus boopis. (See Calman
idem., page 227, figure 135).

JOINTED EPIPODITES OF*CALYMENE AND CERAURUS

Another distinct feature brought into prominence by recent photo-
graphs is that of the long, slender, rounded jointed appendages that
occur in both Calymene and Ceraurus. In slide 109, plate 98, figure
I, these appendages are faintly seen, but with a very strong arc light
they can be successfully photographed as shown by figure 2, plate 97.
They are formed of long joints slightly expanded at their distal end
and about three times as long as their diameter ; these were attached
to a larger proximal joint, figures 1, 3, 6, plate 97; figures 1-3, plate
104, and appear to have been nearly as long as the exopodite and to

1W. T. Calman, Treatise on Zoology, Lankester, pt. VII, 1900, fig. 141,
p. 246.

420 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

have had five or more joints. The test of the joints was thin and
readily distorted, as seen in figures 1, 3, 4, plate 97.

Some of the sections, figures 3, 4, plate 97, appear to have cut an
undulating tube in which no joints are cut across. The few slides
illustrated on plates 97, 104 exhibit the principal characters but they
do not indicate as clearly as a direct comparison that these slender
epipodites are smaller than the spiral arm of the exopodites and very
much smaller than the jointed endopodite or leg of the trilobite ; this
is shown by figures 4, 7, 9, plate 98.

A jointed epipodite of this character is unknown to me, but as it
cannot be an endopodite or exopodite and is a distinct recognizable
form of appendage attached to the coxopodite, I think it best to
tentatively refer to it as a peculiar form of epipodite situated above
the exopodite beneath the ventral surface of the pleurotergites. Its
function may have been to keep the branchial filaments or tubes of
the exopodites clear of sediment and by gentle movement provide
a constant supply of fresh water to them.

THORACIC LIMBS OF NEOLENUS, CERAURUS, CALYMENE AND
TRIARTHRUS

The limbs of text figure 21 are very diagrammatic but they express
my present conception of the parts that compose the thoracic limbs
of the four genera named. It may be that the limbs of Ceraurus and
Calymene will seem too complicated for a primitive crustacean, but
all the elements shown appear to be present in the thin sections illus-
trated ; the problem now is largely a question of interpretation and
allocation of parts on the limbs. Dr. W. T. Calman states that the
presence of epipodites and gnathobases suggests that the primitive
crustacean limb was more complex than the simple biramous type.’
Whether this view is correct or not the fact remains that the limb
of the trilobites is far advanced along the line of evolution of the
crustacean limb, also that the ancestors of the trilobite lived long
before the advent of the Cambrian sea over the surface of the
present continental areas. There is no attempt to show the details
of the various parts of the limb, as they are outlined in the photo-
graphs of the sections on the plates and the diagrammatic text figures
11-14 for Neolenus, 16, 20 for Ceraurus, 17 for Calymene, 19 for
Triarthrus.

* Treatise on Zoology. Lankester, pt. VII, 1900, pp. 8, 0.

INO 9 NOTES ON STRUCTURE OF NEOLENUS 421

Neolenus. (A of text figure 21). Ventral view of the coxopodite
and six segments of the endopodite. The broad, flat arm of the
exopodite is represented as attached to the limb at the proximal end
of the basipodite and both join the distal end of the coxopodite in

ee ee SS SS

Cx Vee STIRS

Ep.)--

if III =.”

ty =
2 aT NARA WR KS ----- Ee C

CWO
or EERE
5 Ee

Fic. 21.—Thoracic limbs of A = Neolenus; B—=Ceraurus; C—=Calymene,
and D= Tnriarthrus.

Legend. cx.=coxopodite. en.—=endopodite. ex.—exopodite. ep.= fim-
briated epipodite. ep. (2) jointed epipodite.

In fig. A, I1=coxopodite. 2—basipodite. 3—ischiopodite. 4—=merop-
odite. 5—carpopodite. 6—propodite. 7—dactylopodite with terminal
spines. Figs. B, C, D have the same joints in the endopodite as fig. A.

A, B and C are ventral veins, and D a dorsal view of the limb.

such a manner as to leave the fringed exopodite free to maintain a
horizontal position above the endopodite; above and dorsal to the
exopodite the plate-like epipodite is located; whether this is its
natural position or whether it was located so as to be more or less
between the endopodites is unknown, but from the location of most
epipodites on the limbs of recent crustaceans it was presumably

422 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

above both the endopodite and exopodite. A section of the coxopo-
dite which is assumed to be sub-triangular in outline is outlined
at (a).

Ceraurus. (B of text figure 21). Ventral view with the exopodite
above the endopodite and the elongate slender epipodite outlined
in the figure above the exopodite; although in a natural position it
was probably just above the exopodite, which would place it back
of it in the outline sketch; the second or fimbriated epipodite is
represented as attached to the posterior side of the coxopodite near
its distal end ; several sections indicate that it may have been attached
to the posterior margin of the broad dorsal or upper side of the’
coxopodite. (See figure 1, plate 99; figures 1 and 2, plate 100.)

The spiral arm of the exopodite shows only its lower or ventral
side and the drawing of it and the attached slender tubes is purely
mechanical ; the manner of attachment of the tubes to the spiral arm
is indicated in text figures 17, 17a of the exopodite of Calymence.

GEEP 7

<a ee |
tig Vt

Fic. 22—Outline of a coxopodite with sections drawn across it at various
angles for the purpose of illustrating how varied the outline of the sections
may be when a fossil coxopodite is cut at different angles. Some of these
are shown in figs. 6 and 9, pl. 99; all on pl. 101; figs. 1 and II, pl. 104.

Calymene. (C of text figure 21). The description of the thoracic
limb of Ceraurus applies very closely to the limb of Calymene; they
undoubtedly differ in details but in the sections it is difficult to deter-
mine to what extent except in the endopodites, and that the coxopo-
dite of Ceraurus is probably shorter than that of Calymene. The
joints of the endopodite of Calymene appear to have been rounder
and less flattened and expanded at the distal end.

Triarthrus. (D of text figure 21). The thoracic limb of Triarth-
rus, like that of Neolenus, is known from more or less flattened
specimens of it, while the limbs of Calymene and Ceraurus have been
seen only in sections cut across them at various angles. The coxopo-
dite is elongate, flattened so as to be deep on the sides, broad on the
dorsal side, and thin on the ventral margin; the four proximal joints
of the endopodite are flattened and the two distal joints rounded in
cross section. The exopodite is more complicated than usually
appears on the specimens showing the dorsal view, which is the one
represented by D, figure 21. The dorsal view shows a long arm
crossed diagonally by numerous narrow joint-like segments, and
these are extended into long, slender, round filaments that judging

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 423

from the branchial tubes of recent crustaceans, were slender tubes;
on the dorsal side the narrow segments are not seen, but longer seg-
ments of a closely jointed arm that is well shown by figure 20, plate
95, of these notes, and in several of Beecher’s specimens ; the uncom-
pressed undistorted form of the arm is best shown by figures 22, 23,

Fic. 23.—(X 12) Exopodites of Tri-
arthrus becki Green. Photograph from
specimen No. 204. Peabody Museum,
Yale University.

plate 95, which is a dorsal view, the narrow segments having been
detached from and pushed up off the jointed arm beneath.
Raymond’s diagrammatic outline of the thoracic limb of Triarthrus
(page 126, figure 33) has on the exopodite a long solid proximal
segment with fringing filaments corresponding to those of the closely
jointed distal portion of the arm; this is based on specimen No. 204
‘ a

‘These are not true segments but a series of closely joined supporting
sheaths of the fringing filaments. See exopodite of Triarthrus, fig. 23.

424 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

of Beecher, which is represented by a diagrammatic outline on page
155, figure 42. A careful study of the exopodites on specimen 204
and a comparison of them with the ventral side of other exopodites,
shows them to be preserved in a natural condition up to the point
where a secondary deposit of pyrite has merged the diagonally
arranged supporting bases of the filaments into a continuous surface.
On one of the posterior of the exopodites of 204 the process of
merging the bases of the filaments is confined to the anterior side of
the arm, and a few of them have escaped altogether. Sometimes
the secondary deposit of pyrite forms a roughened botryoidal surface
and in others it may be quite smooth.

From a study based on all the specimens available I think that
the layer of supporting sheaths extends up to the point where the
last proximal filament occurs and that the diagrammatic illustration
(figure 33) of Raymond is incorrect.

The presence of an epipodite on the thoracic limb of Triarthrus
has not been confirmed by additional evidence since the appearance
of my paper of 1918, plate 30, figure 19. I have examined the speci-
men (No. 65525, U. S. N. M.) several times and can only repeat
what I said in the description of the figure: “ Photograph of a speci-
men that appears to indicate the presence of epipodites.” It may be
that the work that is soon to be done on a large number of speci-
mens of Triarthrus may reveal more of this peculiar structure and
prove or disprove that it represents an appendage independent of
the endopodite and exopodite. Beecher largely obtained his remark-
ably fine results by working down on the ventral side of the trilobite,
which would prevent his finding any small epipodite that might be
attached to the dorsal side of the distal end of the coxopodite. As
a tentative suggestion I still retain the outline of a small epipodite
on the limb of Triarthrus.

SUPPOSED SPIRAL BRANCHIA IN SPECIMEN OF CALYMENE
FROM OHIO

Mr. S. A. Miller called attention to a specimen of Calymene from
the Cincinnatian series of Ohio, in which the fixed cheeks of the
cephalon had been worn through so as to expose what he thought
might be the cast of a spiral appendage.’ The illustration strongly
suggests that it is the arm of an exopodite such as occurs in the
sections of specimens from the Trenton formation of central New
York, but the examination of the specimen now at the U. S. National

* Journ. Cincinnati Soc. Nat. Hist., Vol. V, 1882, pl. 5, fig.8.

INO sr7 > * = NOTES ON STRUCTURE OF NEOLENUS 425

Museum shows that the ends of the posterior thoracic pleure have
been pushed up against the inside of the pleural lobe of the cephalon
so that when seen from above in the closely enrolled specimen they
resemble the segments of the arm of the exopodite of Calymene.
Dr. E. O. Ulrich was first to explain this curious and misleading
specimen.

INTERNAL ORGANS

Alimentary canal—Dr. Raymond adopts the view of Bernard
(1894) and Jaekel (1901) that the alimentary canal of the trilobite
was large, and publishes a drawing of a section of Ceraurus and one
of Calymene (figures 22, 23, page 79) in support of it. My dia-
grammatic figure (1881, plate 4, figure 6; 1918, plate 28, figure 3)
merely indicates the position and not the character of the canal,
although figure 7, plate 3, 1881 shows the large “intestine” of
Ceraurus. As I had occasion since 1918 to study the alimentary tract
of crustaceans associated with Neolenus serratus, I also examined
the photographs of many of the translucent sections of Calymene
and Ceraurus to ascertain what light they might throw on the gen-
eral question of the internal organs of the trilobite. The result is
that I am now illustrating a number of the sections on plate 95, and
describing them somewhat in detail: the evidence of the alimentary
canal will first be considered.

In all of the many hundreds of sections of trilobites that I cut
from the dark, fine grained Trenton limestone the visceral cavity
beneath the axial lobe and the ventral appendages had been replaced
by white calcite which outlined the parts with wonderful distinct-
ness in contrast with the dark limestone matrix ; the dorsal test and
hypostoma were also usually replaced by calcite and often blended
in with the calcite filling the visceral cavity, but sometimes distinctly
separated from it by a clearly defined line; when any interior organ
such as the alimentary canal was filled with food and mud while
feeding or by infiltration after the death of the animal with fine, ©
black calcareous ooze or silt, the canal retained its outline as shown
by figures I, 2, or it may have been distorted and forced out of place
by compression, figures 3-12, plate 95. The section of figure I was
probably at about the fourth thoracic segment, and it is probably the
least compressed and distorted transverse outline of the alimentary
canal of Ceraurus in the collection. The round dot on each side may
be the section of an hepatic tube or sections of the flexor muscles. A
very delicate white line indicating a firm structure arches from the
two round lateral dots through the upper part of the dark alimentary
canal that is a section of the articular projection of the next posterior

426 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

mesotergite which has been pushed down a little; in figure 2 (speci-
men No. 205) the alimentary canal is nearly round and compares
favorably with the section of figure 1; in figures 4-7, the canal has
been somewhat flattened out by compression, also in figure 8, which is
a slightly diagonal section; figures 8, 9, 10, show the canal displaced
and distorted. What may be a portion of the canal or the heart in
Calymene occurs in the upper portion of the axial lobe in the sections
represented by figures 16, 17. As far as known to me none of the
sections show the alimentary canal beneath the cephalon, but as Ray-
mond states (pp. 80, 81), this is well shown in Cryptolithus from
Bohemia. The restorations by Raymond, figure 24, page 81, of a
longitudinal section, and figure 29, page 93, of a dorsal view of the
alimentary canal are probably as nearly correct as can be made from
available data.

Abdominal sheath—The reproduction of the drawings (page 79,
figures 21, 22) by Raymond of the “ abdominal sheath,” traced from
photographic enlargements of slides No. 118 and No. 97, are not
very conclusive evidence of the presence of such a sheath. The
“ dorsal sheath ” of slide No. 118 is shown by our figure 16 plate 95,
where it seems to represent an arched space filled in with the dark
soft mud that constituted the matrix in which the trilobite was buried.
_ The sheath of slide No. 97 may be a section of the articular exten-
sion of an adjoining mesotergite. There is in slide No. 27 (figure 1,
plate 95 and figure 4, plate 103) a similar slender line arching over
the upper part of the section of the alimentary canal that appears
to have a definite outline like that of sections of the dorsal test (see
figures 3, 4, plate 96).

Figures 3 and 4, plate 96, illustrate how it is possible that the so-
called abdominal sheath is merely a section of the anterior part of the
mesotergite where a vertical section cuts through the dorsal test, its
anterior ventral extension and posterior articular extension. Such
a section when cut transversely would give a section such as that of
figure 4, plate 103.

Hepatic glands —Under the heading of gastric glands (page 82)
Raymond gives an historical outline of opinions of authors on the
interior genal markings of trilobites, and concludes that they more
likely represent either traces of the gastric ceca or of the circulatory
system, and that the present evidence seems to be in favor of assign-
ing to them the function of lodging the glands which secreted the
principal digestive fluids. He speaks of similar markings occurring
in Naoria and Burgessia of Walcott (1912, plates 27, 28), but does
not state that the hepatic ceca of those genera are not markings

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 427

-on the test but are in the structure of the substance filling the space
between the dorsal test and ventral membrane. Reference will be
made to the probable hepatic glands of the trilobite in a paper that I
now have in preparation on Marrella, Burgessia, Naoria and other
Middle Cambrian crustaceans.

Heart—Raymond states (page 85): ‘‘ Nothing has been seen in
the sections of Ceraurus and Calymene suggesting a heart.” I
thought the same until I noticed in slide No. 115 of Ceraurus, and
No. 118 of Calymene (figures 16 and 17, plate 95), a dark, rather
strong, arched line above the position of the alimentary canal that
did not appear to be chitinous or to have any relation to the dorsal
test. In both slides the arched line terminates at what may be sec-
tions of the dorsal flexor muscles of the axial lobe of the thorax;
it is rather sharply marked by its dark color in contrast with the
white calcite of the visceral cavity, and has a substantial thickness.
It is customary to think of the elongate heart of a crustacean as
circular or oval in outline, and it was not until I saw Dr. J. S. Kings-
ley’s* drawing of the heart of Limulus as it appears in a transverse
section of the abdomen that it occurred to me that the elongate
arched line of slides 115, 118, might represent the heart of the trilo-
bite. In the abdomen of Limulus the heart is transversely flattened
and, with the large branchio-cardiac veins, extends nearly across the
visceral cavity. This is merely a suggestion, but as I do not think
the arched lines beneath the axial lobe of the dorsal test can repre-
sent the abdominal sheath or the articular anterior extension of the
mesotergite, the theory that they may represent the heart may be
worth consideration.

The heart of Squilla mantis is elongate, tubular and extends nearly
the whole length of the thoracic and abdominal regions.* One can
readily imagine such a heart flattening and curving over a mud-dis-
tended alimentary canal when the space was narrowed by compres-
sion between the dorsal test and ventral integument of the trilobite.

Musculature —Dr. Raymond has presented the known evidence
of muscles of the trilobite, but as he has not illustrated slide No. 114
which he mentions, I am giving a reproduction of a photograph of
it in which the four dark spots occur, the upper two of which may
represent the dorsal flexor muscles (figure 19, plate 95), also figures
of five slides in which one or more similar spots occur. In slide No.
119, figure 18, plate 95, four dark spots occur almost as in slide No.

* Anniversary Mem. Boston Soc. Nat. Hist., 1880, pl. 2, fig. 4.
* Calman, Treatise on Zoology, Lankester, pt. VII, 1909, 324.

428 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

114; in figure 2, plate 95, of slide No. 205, three such spots occur on
the right side along with two irregular spots; figure 17, slide No. 115,
has a large ventral spot and two small dorsal spots; figure 16, slide
No. 118, has two dorsal spots, and slide No. 27, figure 1, has twin
circular dots on each side of the axial visceral cavity that indicate
two ventral muscles near the cephalon. Raymond states that slides
numbered 131, 140 and 199 also show similar spots.

The presence of these dark spots indicates a hollow tube-like open-
ing in the substance of the matter filling the visceral area into which
the silt filtered and replaced the muscle which had been removed
after decomposition. When considering an explanation of the origin
of the spots, I took a small alcoholic specimen of Limulus and cut
out the dorsal carapace so as to leave the alimentary canal and flexor
muscles exposed; the liver had decomposed so that the four strong
flexor muscles were in strong relief; I then turned to Packard’s
drawing of a cross section through the cephalothorax in front of
the heart, etc., of Limulus* and found the sections of four flexor
muscles in the same relative position as the four spots in the sections
of Ceraurus. In Limulus sections cutting across the flexor muscles
further back beneath the cephalothorax show them in a different
position, but I think we may reasonably infer that the spots in Cerau-
rus indicate the position of its flexor muscles. The replacement of
casts of tubes and other organs in soft bodied animals by infiltration
after the animal has been buried in silt or fine mud is beautifully’
illustrated by the replacement of tubes, etc., in the Middle Cambrian
fossil medusee.” .

In some instances (figures 17, 18, 19, plate 95) the lower rounded
triangular spots may be sections of the inward extension of the axial
processes of the mesosternites of the dorsal test, as indicated by the
sections represented by figures I, 2, 3, 5-7, 10, plate 102. The upper
spots do not permit of this explanation, and some of the ventral ones
may be filled-in holes left by the decay of the muscles.

USE OF PYGIDIUM IN SWIMMING

Raymond presents several arguments in support of the theory that
trilobites with large pygidia used them in swimming (pages 72, 73),
but it is not easy to imagine a trilobite using its pygidium as an active
agent in swimming or darting backward through the water to escape
its enemies. The large pygidia were encumbered with a load of limbs

* Anniversary Mem. Boston Soc. Nat. Hist. IV, 1880, pl. 2, fig. 2.
* Monogr. U. S. Geol. Survey, Vol. 30, 1898, pl. 4, figs. 7-12; pl. 17, fig. 3a.

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 429

composed of at least a separate endopodite and exopodite that were
more adapted to creeping or walking and swimming forward than
to being flattened against the ventral surface of the pygidium so as not
to act as a drag in any quick motion of the pygidium or the backward
movement of the animal. All the restorations of the trilobite by
Beecher, Raymond, and Walcott indicate a ventral surface with the
appendages so arranged as to facilitate a relatively slow forward
movement when swimming or crawling. The species with large
pygidia were well adapted to lying close to the bottom partly buried
in the sand, mud or silt, which would have given them ample pro-
tection.

The species with small pygidia greatly outnumber those with large
pygidia, and they survived in great numbers, although powerful
enemies existed as far back as Middle Cambrian time. Sidneyia
inexpectans’ must have been a strong, rapid swimmer, and with its
broad fan-like caudal fin could have readily overtaken and captured
with its great chelate cephalic limbs any swimming trilobite.

COXGPODITES AND, TRAILS OF TRILOBITES

Raymond long ago called attention, in the description of a new
species of /sotelus, to the relation between the long “ gnathobases ”’
of /sotelus and certain markings on sandstones from the Chazy for-
mation. I had not noted this when preparing my paper of 1918 on
the Appendages of Trilobites, and hence did not refer to it. I then
called attention to tracks and trails supposed to have been made by
trilobites, and spoke of the curious and interesting trails in which
the impression of long endopodites (coxopodites) were very numer-
ous, and gave several illustrations of them.* Some of the trails are
so strikingly similar to what a trilobite would naturally make that
there does not appear to be any other interpretation of them as there
is no form in the associated invertebrate life that I can imagine
making such trails.

ISOTELUS MAXIMUS Locke

Raymond concludes that the endopodites of Jsotelus were com-
posed of cylindrical segments (page 75), but I find that the specimen
of Jsotelus maximus Locke (Walcott 1918, plates 24, 25; U. S.
National Museum Catalogue No. 33458) shows very distinctly verti-

1Smithsonian Misc. Coll., Vol. 57, 1911, pls. 2-5.
? Ottawa Naturalist, Vol. 24, pp. 131-133.
* Smithsonian Misc. Coll., Vol. 67, No. 4, 1918, pls. 38-40.

430 SMITHSONIAN MISCELLANEOUS COLLECTIONS —— VOL. 67

cally flattened coxopodites and a slight flattening of the basipodite
and of three proximal joints of the endopodites; the other joints of
the endopodites appear to be rounded on the ventral side, but none
of them show a complete transverse section of the joints; it is also
to be recalled that the appendages of this specimen underwent more
or less maceration and compression when embedded in the calcareous
mud that now forms its matrix, and that it also was more or less
abraded before being rescued from quarry rubbish and the wagon
seat of the teamster who picked it up.

Raymond was unable to see the slender markings (page 36) that
Walcott represented in the diagrammatic figure of the appendages
of Isotelus maximus (Walcott 1918, plate 25), but I find they are
still on the specimen and can readily be seen by reflected light when
the surface of the rock is washed clean of dirt and finger marks and
kept wet; the slender fimbrize-like exopodite markings were evidently
above and not below the endopodites, although the Walcott figure
(Science, Vol. 3, 1884, page 280, figure 1) has the slender fimbriz.
apparently below the two posterior endopodites on the right side of
the figure, but the endopodites are outlined in the drawing from a
slight and faint impression on the rock that leads to the distal joints
which are imperfectly preserved. If the entire endopodites were
present they would be above the fimbriz in the drawing, or below
them if the animal was in a natural position.

The coxopodites of Jsotelus were probably used to aid in pushing
the trilobite forward when on a sandy or muddy surface, as shown
by trails on the surface of sandstones of the Middle and Upper Cam-
brian (Walcott, 1918, plates 37-40), but I think the short stout legs
enabled the animal to creep about without difficulty both on the bot-
tom under water, and in the shallows on the beach between tides.

ORDOVICIAN CRUSTACEAN LEG

Raymond (pages 56, 57) had difficulty in dealing with the slender
crustacean legs (endopodites) that occur on the surface of limestone
shale from the Trenton Point Pleasant formation near Covington,
Kentucky. Walcott illustrated (1881, plate 6, figure 5) two of the ~
legs, stating (page 207) that they compared with the leg as restored
in Calymene. Walcott again in 1918 figured five of the legs (plate
36, figures 2 a-d) as they occur on specimen No. 65532 (U.S
National Museum catalogue) and gave a restoration of the leg
(figure 1) with its eight joints which include a long slender distal
joint (dactylopodite) ; a propodite about half as long as the distal

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 431

joint; three joints (carpopodite, meropodite, ischiopodite) a little
longer than the propodite; a sixth joint (basipodite) about as long
as the propodite; a short seventh joint (coxopodite), and a still
shorter eighth joint which corresponds to the precoxal joint of the
thoracic leg of Nebalia bipes, as described by Hansen.’ This leg is
unlike that of the limb of any known trilobite as it has neither the
long, strong coxopodite nor the broad joints of the endopodite. It
also differs in the character of the joints and the manner of their
articulation.

Raymond ( page 57) was unable to count more than seven joints
on any of the specimens of the legs; he evidently failed to see the
small precoxal joint which occurs on four of the legs.

NOTE ON OCCURRENCE OF THE OLDEST KNOWN TRILOBITE

The oldest Cambrian fauna containing trilobites is the Nevadia
weeksi fauna of Nevada. This fauna continues far below the Meson-
acis gilberti fauna of the upper portion of the Lower Cambrian and
there are no trilobites known from the 5000 feet (1524 m.) of strata
in which it occurs except genera of the Mesonacidae, Nevadia,
Holmia, Olenellus, except a fragment of a Ptychoparia somewhere
in the upper 400 feet.’

*Nevadia weeksi Walcott has a large cephalon, twenty-eight thor-
acic segments, a very small plate-like pygidium without a defined
segment.”

Holmia rowei Walcott has a large cephalon, sixteen thoracic seg-
ments and a very small pygidium with one distinct segment.

The above two species are all that were found in the lower strata.
A fragment of what may have belonged to an Olenellus occurs 1000
feet (304.8 m.) or more above and over 3000 feet (914.4 m.) above
the cephalon of a trilobite tentatively referred to Olenellus, O.
claytoni.°

There are no traces in this primitive fauna of any trilobite with a
large pygidium and the early stages of growth of the young of the
Mesonacidae all have a very large cephalon and a minute pygidium.

The genera Microdiscus and Eodiscus appear in the later forma-
tions of the Lower Cambrian series. It would seem that if these

+ Ann. and Mag. Nat. Hist. (6) XII, 1893, p. 422.

* Smithsonian Misc. Coll., Vol. 53, No. 5, 1908, p. 180.
* Smithsonian Misc. Coll., Vol. 57, No. 6, 1910, pl. 23.
*Idem, pl. 20.

*Idem, pl. 40, figs. 9-11.

432 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

forms with a large pygidium were the primitive type of the trilobite
they should occur in great variety and numbers in the earlier Cam-
brian faunas.

Raymond has assembled an interesting series of observations to
sustain the view that the primitive trilobite was a flat, free swimming
form with a subequal cephalon and pygidium, and his discussion will
serve to stimulate the search for more and more primitive faunas
in the older sedimentary formations.

CONCLUSION

The additional data added in these notes relates to the thoracic
limbs of Neolenus, the spiral exopodites and epipodites of Calymene
and Ceraurus, the exopodites of Triarthrus, and the large, clear pho-
tographs of the thin section of Calymene and Ceraurus. The items
mentioned are not at all sensational in character but they add to our
knowledge of the structure of the limbs of the trilobite. Each item
has taken much time and energy to work out as it involved the
examination of many specimens, the cutting of thin sections, and the
taking of many photographs.

Copies of the principal photographs will be sent to at least sixteen
of the museums of the world where special attention is given to
invertebrate paleontology, in order that students may have access
to some of the evidence on which my conclusions are based as direct
from the specimens as it is possible to present it.

My interest in the organization of the trilobite has been revivified
by this study and I hope to add a little more to what is now known,
in the course of two or three years.

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434 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE ot
PAGE
Neolenus serratus Rominger.. ic. 06.0 e002 ee 0s< 00 0ss 24 0208300237 qe eee
Fic. 1. (Natural size.) Photograph of a specimen preserving more or
less of 15 ventral limbs, the antennules and one of the
caudal rami on the right side. One ventral limb has been
torn away at 7 and the shaft of an exopodite is partly pre-
served above limb No. 9; the latter is clearly shown in
fig. 2, pl. 93. The 4 anterior or cephalic limbs as enlarged
are shown by fig. 1, pl. 93, and the 8 posterior limbs by fig. 2,
pl. 93. The numbers 1-4 = cephalic limbs; 5-11 = thoracic
limbs; 12-16 = pygidial limbs.

The matrix of this specimen is on the upper portion of a piece of
shale illustrated by pl. 15 of this volume (Smithsonian Misc. Coll.,
Vol. 67, 1918). U.S. National Museum, Catalogue No. 58588.

2. (xX about 6.) The coxopodite B, C, D, of text fig. 15 (p. 383)
enlarged and lighted from the lower right side so as to
bring out the ventral and proximal spines on the coxopodite
D. The lower ventral margin of coxopodite C passes
beneath D, so as to conceal its ventral row of spines.
Coxopodite B is free but molded over the impression of the
pleural segment of the dorsal test; it has a few ventral
spines, as has the basipodite (2), and the ischiopodite (3),
and the meropodite (4).

The lettering and numbering is the same as for text fig. 15 (p. 383)

The specimens illustrating Neolenus serratus are from locality
35k, Middle Cambrian: Burgess shale member of the Stephen
formation, on the west slope of the ridge between Mount Field and
Wapta Peak, 1 mile (1.6 km.) northeast of Burgess Pass, above
Field, British Columbia, Canada.

Calymene senaria Conrad... cis cas sie oeistac stata cine so bein ss eclels elena 304
Fic. 3. (X6.) (See fig. 4, pl. 99). Transverse thoracic section on
which Raymond (p. 53, fig. 15) based the “ ball-and-socket ”
joint theory of the mode of attachment of the ventral limb
of this species. The joint being at x. (See also figs. 4 and
5). (Slide No. 63; M. C. Z:).
4. (X8.) Portion of a transverse thoracic section in which a
“ball-and-socket ” joint-like effect occurs near the distal
end of an endopodite at x. (Slide No. 48, M. C. Z.)

Ceraurus pleurexanthemus Green. is... 2.2. ace os sen sleslen se ee eee 400
Fic. 5. (6.) Portion of a transverse thoracic section in which a
“ball-and-socket ” joint-like effect occurs where a broken
and distorted endopodite comes close to another fragment
of an endopodite at x. (Slide No. 230, M. C. Z.)

The specimens illustrated are from the Ordovician: upper por-
tion of the Trenton limestone;.1 mile (1.6 km.) east of the middle
fall of Trenton Falls, on the West Canada Creek, in the town of
Russia, Herkimer County, New York.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 91

LIMBS OF NEOLENUS, CERAURUS AND CALYMENE

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NC. 7, PL. 92

EXOPODITES AND EPIPODITES OF NEOLENUS

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 435

DESCRIPTION OF PLATE 92

PAGE

Neolenus Sent (Rominger) (see pl. 20 of this volume, published in
Gis)" .o Paap ash bb OE ad Eo pid CE eee 369-375, 380-394

BIG Ta GX Untouched photograph of two of the large epipodites

of the thoracic limbs, showing their tenuous character,

minute marginal and carinal spines, the lines of the carinae,

and the distinctness of the large proximal and small distal
TOMIMES,, -og'a ao FOS S'S Ao Bion CERO Carn ee ice gerne on 3890

2. (X3.) Same photograph as that represented by fig. 1, on which
the minute marginal and carinal spines have been outlined
by darkening the background.

The specimen represented by figs. I and 2 is the same as
that represented by fig. 3, pl. 20, Smithsonian Misc. Coll.,
Vol. 67, No. 4, 1918, U. S. National Museum, Catalogue No.
65515. Photograph by R. S. Bassler.

3. (x 3.5.) Untouched photograph of a slightly greater enlarge-
ment of the upper epipodite of fig. 1, in which the base of
the carinal spines is more clearly indicated.

3a. (xX 3.5.) Untouched photograph of the lower margin of the
epipodite represented by fig. 3, in which the fine spines are
more clearly defined. The spines should be compared with
laminated filaments of the exopodite as shown on figs. 5
and 6. Photograph by L. W. Beeson. U. S. National
Museum, Catalogue No. 65515.

4. (X 3.5.) Photograph of the matrix of one of the lower epipo-
dites on the specimen illustrated by figs. 3 and 4, pl. 20, of
brochure No. 4 of this volume (67), enlarged so as to show
the carinal spines which have been retouched to bring them
out more clearly.

Photograph by L. W. Beeson. U. S. National Museum,
Catalogue No. 65515.

5. (X3.) Untouched photograph illustrating narrow, fringing
lamellar filaments of the thoracic exopodites. This enlarge-
ment is from the upper portion of the specimen represented
by figs. 1 and 2, pl. 23, of brochure No. 4 of this volume (67).
The exopodites are lying above and on the endopodites.
Nearly all details of structure were lost in the reproduction
OlatMenomletinal wmotIuesumis santo eee eee eos sine ciara 3902

Compare lamellar filaments with fine fringing spines of
epipodites, figs. 1-3. U.S. National Museum, Catalogue No.
65521. Photograph by L. W. Beeson.

6. ( <4.) Untouched photograph of posterior exopodites on the
specimen represented by fig. 3, pl. 19, of this volume, in
which the exopodites are lying above and on the endopo-
dites. The photograph was made from the matrix. The
lamellar elements or filaments of the posterior margin are
clearly shown. In both of the exopodites the distal joint
has been pressed slightly out of position and the short
fringing filaments appear as a portion of the body of the
joint which gives a false impression as to its form. U. S.
National Museum, Catalogue No. 65514. Photograph by
TL, Wg BCC osa et Sai a Sian cee cone euced oC Non eee ae 388

The specimens represented on this plate are all from locality 35k,
Middle Cambrian: Burgess shale member of the Stephen formation,
on the west slope of the ‘ridge between Mount Field and Wapta Peak,
1 mile (1.6 km.) northeast of Burgess Pass, above Field, British
Columbia, Canada.

436 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PEATE 93

Legend
ex = exopodite. car = carpopodite.

cox = coxopodite. pro = propodite.

bas = basipodite. dac = dactylopodite.

mer = meropodite. cl=terminal claws.

isch = ischiopodite.

PAGE
IN COVAMIS SHAS ICIOIMESP So 0006 accos coo s0aboeeDudeoSbunr 369-375, 380-304
Fic. 1. (3.3) Reproduction of a photographic enlargement of the

four anterior limbs of the right side of fig. 1, pl. 91, (Speci-
men 58588) to illustrate the form of the cephalic limbs,
which is similar as far as known, except in a few minor
details, to that of the limbs of the thorax and pygidium... 390

2. (X 3.3) Reproduction of a photographic enlargement of the
eight posterior limbs of the right side of fig. 1, pl. 91, to
illustrate the spiniferous coxopodites and the close attach-
ment of the endopodites to them. The jointing of the endo-
podites is clearly preserved, also the ventral margin of the
endopodites, but their dorsal (anterior in the figure) margin
has been cut away from the coxopodite and basipodite of
three of the limbs where they rested on the ventral (pos-
terior in the figure) margin of the next anterior limb and
concealed the margin and spines of the ventral side. Three
of the limbs show the “notch” of Raymond between the
coxopodite and basipodite. Note the strong group of spines
on the basipodite and ischiopodite and that the grouping of
the ventral spines midway of the basipodite is successively
nearer the distal end of the ischiopodite, meropodite, carpo-
podite, and propodite where it is at the end of this joint and
the two succeeding distal joints. The large spine with the
smaller spines corresponds to the ventral angle of the flat-
tened joints of the endopodite of Triarthrus becki.*

! Walcott, Smithsonian Misc. Coll., Vol. 67, 1918, pl. 30, fig. 20.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 93

fips

—
tw, as “

LIMBS OF NEOLENUS SERRATUS

SMITHSONIAN MISCELLANEOUS COLLECTIONS

= ES =

—=-
=e SSS s— ce
p H — \
1 good OY = ae = AN \ A)
- A Fh HOY wong Th AVN HN
q y = X

KO a iE d |
| Se Nn

RESTORATION OF VENTRAL SURFACE OF NEOLENUS SERRATUS (Rominger)

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 437

DESCRIPTION OF PLATE 04

Legend
d.s.— dorsal shield. en. = endopodite.
hy. = hypostoma. ep. = epipodite.
a. =antennules. ex. = exopodite.
an, = anal aperture. cx.= coxopodite.
c. ¥.= caudal rami. v.1. = ventral integument.
PAGE
NigulemiEs SERrattes 1 OMINGET)) fora sci0 2» sie -d.<clein eine ces em die aeas ereete Saleen 392

Fic. 1. (About twice the large-sized specimens of the species.) This

outline restoration differs in details from that published in

1918 (pl. 31) and in the omission of the small epipodite and

exite attached to the coxopodite of the post-cephalic limbs.

The observer should note that the coxopodite and endopodite are

seen from their narrow lower or ventral side; that the exopodites lie

nearly in a horizontal position above the endopodites and that the

epipodites are in a nearly flat position between the ventral membrane
and the exopodites.

The arrangement of the cephalic limbs is diagrammatic, being

based on their known position in Triarthrus becki and incomplete
data for Neolenus.

438 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DES CRIPMIONT OK SEI AWeE sos
PAGE

Ceraurus pleurexanthemus Green..... os so«: 2<+ 4-0 2 ess ee 304-412

Fic. 1. ( 4.) Transverse section at about the fourth thoracic seg-

ment of a partially enrolled specimen showing alimentary
canal; filamentous appendages on the left side close to the
coxopodite of the thoracic limb and on the right side a
spiral-like structure similar to that in fig. 1, pl. 906. In the
lower part of fig. 1 there are circular dots on the line of the
dorsal furrows of the dorsal test that may indicate the posi-
tion of flexor muscles. (Slide No. 27, M. C575)

(x 4.) Transverse thoracic section of an enrolled specimen
with a distorted section of the alimentary canal. (Slide
No. 205, M. C. Z.)

3. (X4.) Diagonally transverse thoracic section with a small
rounded section of what may represent the alimentary
canal. (Slide No: 65, M. G22)

4. (X 4.) Transverse thoracic section cut obliquely down through
the axial lobe. (Slide No. 244, M. C. Z.)

5. (X4.) Transverse thoracic section with the alimentary canal
compressed as in fig. 6. (Slide No. 83, M. C. Z.)

6. (X3.) Transverse thoracic section preserving the outline of a
somewhat compressed alimentary canal, section of a coxo-
podite of a ventral limb and sections of ribbon-like slightiy
undulating appendages referred to as epipodites. See figs.
2yande4y ple o7.) (slide Now 13) MaiGs 2)

This section was illustrated by a drawing based on a photograph
by veo 1881, pl. 2, fig. 3, and a photograph in 1918, pl. 26, fig. 14.
OO Transverse thoracic section in which the alimentary

a has been greatly distended and distorted; see figs.
Orander2 ss (SlidesNioss ssn»)

8andio. (X 3.) Transverse thoracic section in which an inward
extension or process of the articular fold of the dorsal test
is preserved on the left side at the union of the mesotergite
and pleurotergite and above the coxopodite of the ventral
limb. What may be the displaced alimentary canal is indi-
cated by the transversely oval black space beneath the dor-
sal test of the axial lobe. (Slides M. C. Z. No. 117= fig.
10, and No. 202 = fig. 8.)

9. ( X10.) Transverse thoracic section in which the upper margin.
of the enlarged alimentary canal appears to have been
crowded up against the articular extension of a segment of
the dorsal test as in figures 5, 6, 13. (Slide No. 30, M. CEZ9)

10, (See fig. 8.)

11. ( 4.) Transverse thoracic section of an enrolled specimen
showing oblique compressed section of the alimentary canal
and traces of coxopodites of ventral limbs. (Slide No. 110,
Mi: CaeZ.)

12. (X10.) Transverse thoracic sections with a curiously dis-
torted and displaced alimentary canal. (Slide No. 148,
MaGyZ))

13. (X3.) Transverse cephalic section showing portion of a dis-
placed alimentary canal crowded up against the articular
extension of one of the mesotergites. “(Slide No. 228, M.

me (Sx 4.) “Transverse thoracic section to illustrate what may
represent a collapsed alimentary canal crowded high up in
the visceral space of the axial lobe. (Slide No. 112, M.

17. (xX 4.) Transverse thoracic section showing supposed position
of two dorsal flexor muscles, a triangular section of a coxo-
podite, and on left side portions of three ventral limbs.
(Slide No. 115, M. C. Z

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 95

SECTIONS OF TRILOBITES

IO; 7, NOTES ON STRUCTURE OF NEOLENUS 439

PAGE

BALANCE SEMUTICSCOUMAGG raw aceq ae Meters) asks a aN ews oe ¥ gs do ale we qiacd oe siecle s 304-412
Fig. 14. ( 5.) Transverse section showing an elongate collapsed
alimentary canal crowded up into the thoracic axial lobe;
the entire section is shown by fig. 5, pl. 101. (Slide No. 9,
M-G._Z.)
This section was illustrated by a drawing based on a photograph
by Walcott, 1881, pl. 1, fig. 9.

16. (xX 3.) Transverse thoracic section showing position of two
supposed dorsal flexor muscles and what may be a trace
of the transversely arched heart. (Slide No. 118, M. C. Z.)

18. (<4.) Section similar to that represented by fig. 19, except
that the two dark ventral spots are not quite in the same
position. Attention is called to other details in the descrip-
tion of the slide. (Slide No. 119, M. C. Z.)

19. (X4.) Transverse thoracic section showing supposed posi-
tion of dorsal flexor muscles, section of coxopodites of
ventral limbs, and points of fold of articular projection of
a mesotergite. (Slide No. 114, M. C. Z.)

The slides represented by figures I-19 were made by me and are
now in the Museum of Comparative Zoology at Harvard College,
Cambridge, Massachusetts.

The sections illustrated are of trilobites from the Ordovician:
upper portion of the Trenton limestone; 1 mile (1.6 km.) east of
the middle fall of Trenton Falls, on the West Canada Creek, in
the town of Russia, Herkimer County, New York.

Pincers Dele GaN cic 6 oo Uoabod ooo dodogboomotecoaccuogoGaoboUET 413-415
Fic. 20. ( 15.) Exopodite with the joints of the supporting arm,
flattened and appearing in a slightly oblique position instead
of vertical as in figs. 22 and 23, also diagonally arranged
branchial tube bases and slender flattened tubes. This
specimen was illustrated by Walcott, 1918, Smithsonian
Miscellaneous Collections, Vol. 67, pl. 20, fig. 11.

21. (xX 12.) Long slender branchial tubes matted together so as
to give the appearance of fine flat filaments of which there
are about 40 attached to the bases attached to the arm of the
exopodite. U. S. National Museum, Catalogue No. 68387.

(< 10.) Specimen illustrated by fig. 23 lighted from right side

so as to show the joints of the supporting arm of the exopo-
dite, also the bases of the branchial tubes, more in detail.
This specimen was illustrated by Walcott, 1918, Smithso-
nian Miscellaneous Collections, Vol. 67, pl. 20, fig. 3. U.S.
National Museum, Catalogue No. 65523.

23. (X8.) This specimen reveals the ventral side of the jointed
supporting arm of two of the exopodites and the dorsal
layer of bases of the branchial tubes or filaments which
have been displaced and pushed forward from the support-
ing arm; a portion of two of the endopodites projects from
beneath the exopodites.

The specimens illustrated by figs. 20-23 are from locality 373,

Ordovician: Utica shale; 3 miles (4.8 km.) north of Rome, Oneida

County, New York.

to
rN

440 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 06
PAGE
Calymene ‘senorita Conrad. .4..5 2 eee eee ee Eo 394-412
Fic. 1. (X15.) Photograph of a translucent longitudinal section of a
partially enrolled trilobite in which the exopodites have been
displaced and nine of them cut across so as to illustrate the
spiral structure of the supporting arm. Exopodite number
5 has a number of the branchial tubes or filaments attached
to the arm, and number 6 apparently cuts across the plane
of the insertion of three of the branchial tubes into the
supporting base. A few fragments of endopodites are cut
across in the upper right corner of the photograph. More
of the latter occur further forward in the slide as shown
in fig. 2. The dorsal test of this specimen was exfoliated
except a little of it on the pygidium as shown in fig. 2
(Slide No. 68379 U. S. N. M.) This slide was made
March 8, 10921.

2. (X4.) This is the same section as that illustrated by fig. 1.
It illustrates how difficult it is to obtain a good photo-
graph of the ventral limbs in a small enlargement of the
section of the trilobite in the slide.

3. (<10.) Enlargement of a longitudinal section of three seg-
ments of the axial lobe to illustrate the posterior under fold
of the dorsal test and how transverse sections cut at I, I,
and III would give two sections of the dorsal test, the lower
one or the articular projection of the mesotergite apparently
misled Dr. Raymond in interpreting it as an abdominal
sheath. If the section had been cut nearer the center of the
axial lobe it would have shown the articular extension of
the axial segments about the same as in fig. 4. (Slide
No. 68807, U. S. N. M.)

Ceraurus pleurexanthemus Greeninm. 5-0. 5.01 ates aoc coe eee 304-412

Fic. 4. (X10.) Longitudinal section of the axial lobe cutting the
dorsal test of the cephalon and that of three anterior thor-
acic segments. The vertical white lines I, II, III, pass
through the dorsal test of each segment in the same manner
as the black lines of fig. 3. They cut the infolded posterior
margin and the arched anterior articular extension of the
mesotergite. This explains the section of the dorsal test
with the “Abdominal sheath” of Raymond and an occa-
sional second “sheath” as shown in transverse sections of
the thorax. (See figs. 1, 3, 4, plate 95, and Raymond’s figs.
Pl APS Vs, Fos)

Two sharply elevated tubercles with their hollow interior and
minute canal penetrating the cephalic test are also finely preserved.
Slide No. 159, M. C. Z.)

The specimens illustrated on this plate are from the Ordovician;
upper portion of the Trenton limestone; 1 mile (1.6 km.) east of the
middle fall of Trenton Falls, on the West Canada Creek, in the town
of Russia, Herkimer County, New York.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO 7 PL. 96

SECTIONS OF TRILOBITES

442 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF (PLAGE G7
PAGE
Ceraurus pleurexanthemus oS xsan0 oo uals ook oak ee ce ene ee 304-412
Fic. 1. ( 18.) Enlargement of the round, slender jointed epipo-
dites that occur on the right side of section represented by

fig. 4, pl. 98. The relative size of the endopodite, spiral

arm of exopodite and these slender appendages is shown

by fig. 4, pl. 98. Fig. 2 of pl. 97 shows the jointed character

of the epipodites much more definitely. (Slide No. 120,

M, G..Z))

16.) Enlargement of the round, slender jointed epipo-

dites that occur on the right side of section represented by

fig. 1, pl. 98. The three appendages in this section prove
their jointed character and that they are hollow and either

round or oval in cross section. (Slide No. 109, M. C. Z.)

3. ( X16.) Enlargement of two sections of round, slender undu-
lating epipodites and a portion of one above that has been
sectioned more on the line of its median axis. The posi-
tion of these epipodites in the trilobite is shown by fig. 7,
plate 98. (Slide No. 204, M. C. Z.)

4. (> 18.) Section somewhat similar to that represented by fig. 3,
except that it has a section of a distorted spiral arm of an
exopodite. The position of these parts of the ventral limb
is shown by fig. 3, pl. 98. The difference in direction is
owing to the photographs having been made with the light
passing through from opposite sides of the slide. (Slide
No. 208, M. C. Z.

5. (<18.) A round, jointed appendage that occurs near the hypo-
stoma. Walcott suggested in 1918, p. 195, fig. 15, that it
might have been an antennule. Raymond suggests, 1920, p.
52, that it is an endopodite. (Slide No. 78, M. C. Z.)

6. (<< 18.) Another example of the slender epipodites in which
the jointed structure is not preserved; the relations of these
to the axial lobe of the trilobite is shown by fig. 8, pl. 08.
(Slide No. 135, M. C. Z.)

11. ( 18.) Portions of three spiral arms of the exopodite, the
upper one of which shows traces of spiral structure. The
slide, including the spiral arms, was illustrated by Walcott
in 1881, pl. 3, fig. 5. (Slide No. Psy Wl, (Cy Zo)

is)
—
x

Galymene<senaria (Conrad? s45 5c. ee son oe eee en eee Bar 412
Fic. 7. (> 18.) Portions of the arms of two spiral exopodites show-
ing the manner of attachment of the spiral arm to the
shaft joining the arm to the coxopodite. These were illus-
trated by Walcott in 1881, pl. 4, fig. 4; 1918, pl. 27, fig. 5a.
(Slide No. 32, M. C. Z.)

8. (18) Section cutting spiral arms of exopodites and slender
elongate epipodites; the section containing these parts has
been imperfectly illustrated by Walcott, 1881, pl. 3, fig. 9;
Tors, pl. 27, figs4., (Slide Ne: 297-M.. C. Z.)

9. (xX 18.) Opposite side of the section of fig. 8; this shows the
spiral arms of exopodites and what may be a section of
the narrow side of the joints of an endopodite. (Slide No.
AAO}, Wilk, (Gs 7.)

10. (X16.) Two spiral arms of exopodites. The upper spiral
probably belongs to a different exopodite from the lower
one as the latter has its shaft in position. This slide was
illustrated by Walcott in 1881, pl. 4, fig. 3, and in 1018, pl.
yp sik (CSG IN@, Sin, IME (C, ZZ.)

The slides represented by figures 1-11 were made by me and are
now in the Museum of Comparative Zoology at Harvard College,
Cambridge, Massachusetts.

The sections illustrated are of trilobites from the Ordovician:
upper portion of the Trenton limestone; 1 mile (1.6 km.) east of the
middle fall of Trenton Falls, on the West Canada Creek, in the town
of Russia, Herkimer County, New York.

SNOIL931109 SNOINVIIJOSIN NVINOSHLIWS

ce ae

Le
rh
A Li

3) SALIGOTIHL JO SNOILDSS

ee ee

444 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 068

PAGE

Ceraurus pleurexanthemisiGreenit.c.«. ones oo ate ae eee 304-412
Fic. 1. ( 6.) Transverse thoracic section cutting obliquely across
several endopodites and on the right side fragments of exo-
podites. On the left side there are two slender, short,
jointed appendages that show the outlines of the longitudi-
nal section of the joints; the lower one has three clearly
defined joints and the longer upper one four joints. (See
fig. 2, pl. 97.) In addition there is an oblique section of a
coxopodite on the left side that has fine short spines on the
proximal end and adjoining ventral margin. (Slide No.

TOOw Vien GZ)

(< 6.) Slender short jointed appendage similar in form to
those on the left side of fig. 1. It has five joints, and I for-
merly thought it might possibly indicate an antennule (Wal-
Cott, 1018) pl. 27, es 15) a @olide Now 7os0 Vins Cae) meesee
also fig. 5, pl. 97.

3. (X6.) Transverse thoracic section of a partially enrolled

specimen cutting across the coxopodite and endopodite of
a thoracic leg, parts of a spiral-like section of the arm
of an exopodite, and the proximal portion of a hollow slen-
der appendage similar to that in figs. 1 and 2. (Slide No.
205s Men GeZs)

4. (X 6.) Transverse thoracic section of coxopodites and on the
right side several spinose joints of an endopodite of a
thoracic limb (See fig. 11, pl. 103); on both sides just be-
neath the ventral pleural lobes there is a slender ribbon-like
appendage that is jointed on right side and attached at its
proximal end to a strong base which is probably a section
of the coxopodite (See fig. 1, pl. 97); a similar appendage
occurs below in the section on the right side and below
that a section of an elongate spiral-like arm apparently
terminating in a drawn out portion of the spiral arm.
(Slide No. 120, M. C. Z.) See fig. 1, pl. 07.

5. (x 6.) Transverse thoracic section showing distended alimen-
tary canal, an axial process on the right side, some fragmen-
tary remains of the arm of exopodites, and on the inner side -
of an endopodite a crescent shaped fimbriated margin.
(Seem igs 10) “pliy103))) (Slides Nose i535 Vi Cae Zs) eins
slide was represented by a diagrammatic drawing in the
Raymond Memoir, fig. 23, p. 79.

6. (X4.) Transverse section cutting across the anterior portion
of the thorax and some of the cephalic limbs of a partially
enrolled specimen. The endopodites of the thoracic limbs
are shown in transverse and oblique sections to the right
and to the left of the cephalic appendages above the hypos-
toma; above the latter there are several slender appendages
comparable with those of figs. 1, 3 and 4. (Slide No. 5,
M. C. Z.) This slide was illustrated by Walcott, 1881, pl.
Ti, per, Ee

(X 4.) Transverse oblique thoracic section of coxopodites
with undulating slender appendages beneath the pleural
lobes. (Slide No. 204, M. C. Z.) See fig. 3, pl. 97.

8. (X8.) Transverse section cutting slantingly across the thorax
so as to show on the left side a distorted coxopodite with
slender appendages projecting into the area beneath the
pleural lobes. (Slides No. 135, M. C. Z.) See fig. 6, pl. 97.

iN)

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SECTIONS OF TRILOBITES

NO.

IFXGs TO:

NOTES ON STRUCTURE OF NEOLENUS

445

PAGE

(X< 6.) Transverse thoracic section showing section of dis-

torted alimentary canal; section of a coxopodite on left
side; distorted coxopodite on right side, and several slen-
der appendages on each side apparently belonging with the
coxopodites ; also below sections of the arm of the exopo-
dite. (Slide No. 13, M. C. Z.) This slide was illustrated
by Walcott, 1881, pl. 1, fig. 3, and 1918, pl. 26, fig. 14.

(X Io.) Ova-like bodies imbedded in the calcite filling the

anterior end of a partially enrolled specimen. (Slide No.
33, Moc: Z;)

ERUI EM CMS CITE OOMLAC s 2° 8G oteacas Jigs ds die wcie's 0a edie eta Bea wake 394-

IGS IT.

(xX 6.) Transverse section of an enrolled specimen cutting

across the thorax and pygidium. The oblique sections of
the ends of the six posterior thoracic pleurz are interesting.
This section shows faint outlines of four or five slender
elongate appendages on each side beneath the pleural lobes
and in the pygidium on the right side sections of four
limbs, and on the left side what may be the supporting arm
of an exopodite with five spiral-like segments attached to
it. See fig. 7, pl. 100. (Slide No. 56 M. C. Z.)

All of the sections illustrated on this plate are now in the Museum
of Comparative Zoology at Harvard College, Cambridge, Massa-

The specimens illustrated are from the Ordovician; upper portion
of the Trenton limestone; 1 mile (1.6 km.) east of the middle fall
of Trenton Falls, on the West Canada Creek, in the town of Russia,
Herkimer County, New York.

412

446 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 099
PAGE

Ceraurus pleyrexanthemus. Greem.o.. ic. < sce ose 1s se on 0d ee oe ee

Fic. 1. ( 4.) Transverse section of a partially enrolled specimen
crossing the cephalon on the line of the eye and the thorax
at about the first segment. The detailed description of this
section is given in the text. (Slide No. 22, M. C. Z.) A
drawing of this slide was published by Walcott in 1881, pl.
3, fig. 2, and again in 1918, pl. 27, fig. 12. (See figs. 1 and 2,
pl. 100.)

3. (x 6.) Transverse section of the thorax of an enrolled speci-
men showing section of alimentary canal, with section of
the articular extension of the stergite of the axial lobe, also
on right side a triangular section of the arm of an epipodite
with numerous filaments. (Slide No. 27, M. C. Z.) A
drawing of this slide was published by Walcott in 1881, pl.
3, fig. 7. (See fig. 5, pl. 100.)

6. (X<4.) Transverse section of the thorax of specimen presery-
ing the blade of an epipodite attached to the side of a dis-
torted coxopodite; the outer crenulated margin and a num-
ber of the long filaments are shown. (Slide No. 80, M.
Gy 25) Scene 6,n pla noo:

Calymene senarianContrad® as. <0 cacomecone rae eee Oe 304-412
Fic. 2. (6.) Transverse section cutting across the upper posterior
margin of the cephalon and the anterior upper side of the
thorax in such a manner as to show the filled-in visceral
cavity and the basal portion of several filamentous, presum-
ably thoracic appendages, which are interpreted as epipo-
dites. (Slide No. 45, M. C. Z.) See fig. 3, pl. 100.

A drawing based on this section was published by me in 1881 in
which the right side was restored (fig. 1, pl. 3, Bull. Museum Comp.
Zool., Harvard Coll., Vol. 8); also by a photograph in 1918, pl. 27,
fig. II.

4. (X<8.) (See pl. 91, fig. 3.) Transverse thoracic section cutting
across coxopodites; six slender jointed appendages on the
left side and four on the right side. Midway of the large
coxopodite on the left side there is a rounded depression
with a downward extension of the contents of the axial lobe
extending into it. This slide is the one from which Ray-
mond drew his diagrammatic outline (p. 53, fig. 15) illus-
trating the ‘“ball-and-socket” joint. (Slide No. 63,
WE E7 ZS)

5. (xX 10.) Obliquely transverse section of an enrolled specimen
passing through the posterior portion of the pleural
lobe of the cephalon and pleural lobes of four thoracic seg-
ments, and cutting obliquely across the filaments of several
exopodites. (Slide No. 28, M. C. Z.

A drawing from a photograph of this slide was published by Wal-
cott in 1881, pl. 3, fig. 8, and a photograph of it in 1918, pl. 27,
fig. 13. The exopodites were referred to as epipodites in the descrip-
tion of the figure.

7. (x 6.) Transverse thoracic section cutting lengthwise across
two spiral arms of the exopodites. See fig. 10, pl. 97.
Text description. (Slide No. 31, M. C. Z.)

A drawing from a photograph of this slide was published by Wal-
cott in 1881, pl. 4, fig. 3, and a photograph of it in 1918, pl. 27, fig. 5.
8. (< 6.) Transversely oblique section of an enrolled specimen

cutting across the filling of the thoracic visceral axial
cavity and the bases of two irregular appendages with long,
slender filaments attached to their outer edges. (Slide No.
112, M. C. Z.) See fig. 4, pl. too.

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SECTIONS OF TRILOBITES

NO.

NOTES ON STRUCTURE OF NEOLENUS

9. (x 6.) Transverse thoracic section showing ridges on ventral
integument, sections of coxopodites, and exopodites. See
detailed description in text. (Slide No. 29, M. C. Z.) A
drawing from a photograph of this slide was published by
Walcott in 1881, pl. 3, fig. 9, and a photograph in 1018, pl.
27, fig. 4. (See figs. 8 and 9, pl. 97.)

All of the sections illustrated on this plate are now in the Museum
of Comparative Zoology at Harvard College, Cambridge, Massa-
chusetts.

The specimens illustrated are from the Ordovician: upper por-
tion of the Trenton limestone; 1 mile (1.6 km.) east of the middle
fall of Trenton Falls, on the West Canada Creek, in the town of
Russia, Herkimer County, New York.

447

448 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 100
: PAGE
Ceraurwus pleurexantheqws. San. ac es wie clo as os aoe ese rere eer ene 394-412
Fic. 1. (X20.) Section of a fimbriated epipodite in which the attach-
ment of the fimbriz to the blade is not well shown. Sec-.
tions of somewhat similar specimens are shown by figs, 2-6,
8. The position of the section in this slide is shown by fig. 1,
pl. 99, lower left side. (Slide No. 22, M. C. Z.)

2. (> 20.) Section of a fimbriated epipodite in which the fimbriz
are in contact with the blade, situated on the opposite side
of the axial lobe in the same slide as fig. I (see pl. 99,
fig. T.)

6. (><16.) A blade or arm of the epipodite cut across so as to
show the fluted outer margin and a series of seven fimbrize
that appear to have been cut across close to their base, and
a second series further out that were attached to a base
either in advance of or behind the one preserved in the
section. (Slide No. 80, M. C. Z.)

9. (xX 30.) A section of the calcite replacing the contents of the
body of the trilobite. The crystallization of the calcite has
usually destroyed all traces of the ventral integument, the
test of the limbs, and the membrane of the alimentary canal,
ete, (slide No, 120,)ME GZ)

Galymwene senaniasGonrade: .cnoss cette on can eee hee eee eee 304-412

Fic. 3. (>< 20.) Sections of two fimbriated epipodites. Their posi-

tion in relation to the axial lobe of the trilobite is shown by
fig. 11, pl. 27, Smithsonian Miscellaneous Collections, Vol.
67, 1918. ‘This slide was the basis of the drawing of Wal-
cott, 1881, pl. 3, fig. 1, in which the right side was restored
from the data furnished by the left side of the slide. (Slide
No: 45, Me €2Z)

4. (> 20.) Sections of two fimbriated epipodites. Their posi-

tion in relation to the axial lobe of the trilobite is shown

by fig. 8, pl. 99. (Slide No. 112, M. C. Z.)

(< 18.) Sections of two fimbriated epipodites showing the
fluted margin of the upper one and the strong fimbriz. The
position of the triangular shaped outline of the base or
blade and its position in the slide is shown by fig. 3, pl. 99.
A drawing of this section was published by Walcott in 1881,
pL 3s fies 7a. U(SlideNion27,) ME GZ)

(< 18.) Section of a fimbriated arm that occurs beneath the
posterior portion of the pygidium. See fig. 11, pl. 98. This
may be the arm of an exopodite with the spiral attached to
it asmim tes 7 plo7e, (Slide Nos 56) MiG)

(<< 15.) Section of a fimbriated epipodite the position of which
in relation to the coxopodite of the ventral limb is shown
by fig. 3, pl. 3, Walcott 1881, also same figure on pl. 26, fig.
2, 1918.

This section of this slide also cuts across the filaments and spiral
arm of two or three exopodites that have been displaced and pushed
out against the pleural lobe of several thoracic segments. (Slide
INow2e eine)

The slides represented by figures 1-9 were made by me and are
now in the Museum of Comparative Zoology at Harvard College,
Cambridge, Massachusetts.

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100

67, NO. 7, PL.

SMITHSONIAN MISCELLANEOUS COLL ECTIONS

SECTIONS OF TRILOBITES

450 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OR RIeAgiE sion
PAGE
Calymene senaria-Contad o.5.- 5552 00 een ee eee 394-412

Fic. 1. (X 6.) Longitudinal section of a partially enrolled specimen,
a detailed description of which is given in the text, ante
p. 397. Two other sections cut from this trilobite are illus-
trated. by figs. I and 2, pl. 105. (Slide No. 35, M. © 2)
A drawing from a photograph of this slide was published
by Walcott in 1881, pl. 5, fig. 3.

Fics.2and3. ( 3.) Longitudinal sections of the side of the axial
lobe cutting through the cephalon, hypostoma, several thor-
acic segments, and the basal portions of the ventral limbs.
(Slides No. 15 and 17, M. C. Z.) Drawings from photo-
graphs of these slides were published by Walcott in 1881,
pl. 2, figs, 5 and 7.

4. (X 6.) Section crossing the axial lobe obliquely so as to cut
the anterior coxopodites, then the thickened sternites of
the thoracic segments, and back of these the coxopodites.
(Slide No. 36, M. C. Z.) A drawing of this slide was pub-
lished by Walcott in 1881, pl. 5, fig. 4.

5. (X< 6.) Transverse section cutting obliquely from the first
thoracic segment down through the cephalon, hypostoma
and cephalic limbs. For detailed description see text.
(Slide No. 9, M. C. Z.) A drawing from a photograph of
this slide was published by Walcott in 1881, pl. 1, fig. o.

6. (xX 6.) Transverse section cutting obliquely down across the
cephalon, hypostoma and cephalic limbs. For detailed
description see text. (Slide No. 6, M. C. Z.) A drawing
from a photograph of this slide was published by Walcott
in 1881, pl. 1, fig. 6, and a photograph in 1018, pl. 26, fig. 11.

7. (X6.) Transverse section cutting obliquely down through
from the first thoracic segment across the cephalon, hypo--
stoma and cephalic limbs. For detailed description see
text. (Slide No. 38, M. C. Z.) A drawing from a photo-
graph of this slide was published by Walcott in 1881, pl. 1,
fig. 8, and a photograph in 1918, pl. 26, fig. 9.

Gerauruss pleurexanthemus. Greenh ree eeoeeeeereee
Fic. 8. (X 4.) Transverse section of an enrolled specimen cutting
across the thoracic coxopodites and the spiral arms of sev-

eral exopodites. (Slide No. 147, M. C. Z.)

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SECTIONS OF TRILOBiITES

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 102

SECTIONS OF TRILOBITES

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 451

DESCRIPTION OF PLATE-102
PAGE
Oermurus pleureranihemus Green... 2...) 2 eee ee ee cece seen cence 304-412
Fic. 1. (4.) Transverse section cutting four thoracic segments
nearly on the plane of the dorsal surface of the pleural lobes
and below one axial segment almost vertically so as to
cross the alimentary canal. See pl. 95, fig. 4. The details
of structure shown are described in the text. (Slide No.
2Ady ME Ce Z5)

2. (X65) Transverse section of an enrolled specimen cutting
one thoracic segment almost vertically, and the remainder
of the specimen obliquely so as to bisect several articular
processes. (Slide 39, M. C. Z.)

3. (X4.) Transverse thoracic section to illustrate a section of
the ridge formed by the folding of the test of the axial
lobe of a thoracic segment where the articular extension
of the segment unites with the anterior ventral margin of
the tergite. (Slide No. 205, M. C. Z.)

4. (X4.) Ventral surface of four thoracic segments to illustrate
the anterior articular extension of the mesotergite beneath
the next anterior mesotergite, also where the fold is worn
through the inward extension of an axial process as in fig. I.
(U. S. National Museum, Catalogue No. 68388.)

5. (X6.) Transverse thoracic section showing below the inward
extension of the fold of the articular extension of the
mesotergite, and laterally a slight downward extension of
the test at the dorsal furrows. (Slide No. 123, M. C. Z.)

6. (>< 6.) Longitudinal thoracic section cutting across coxopo-
dites of two endopodites and four infoldings of the articular
process of the mesotergite. See fig. 8. (Slide No. 160,
NMG. Zz.)

7. (Xg.) Transverse thoracic section of the axial lobe cutting the
ventral extension of the dorsal test at the dorsal furrow,
also the anterior articular extension of the mesotergite and
below the processes of the fold of the articular extension
of the mesotergite. (Slide No. 68380, U. S. N. M.)

8. (x 4.) Oblique longitudinal thoracic section of several meso-
tergites of the dorsal test illustrating the folding of the
articular extension of the mesotergite and the outline of the
“processes ” formed by them. (Slide No. 231, M. C. Z.)

9. (X4.) An example somewhat similar to that represented by
fig. 10. This section also shows traces of the cephalic appen-
dages and an axial process beneath the cephalon. (Slide
iINOF 1O9 so Nie“ Ee Z5)

10. (xX 3.) Another example of the cutting across the fold of the
articular process as described in the text. This slide also
has an interesting section of a coxopodite. (Slide No. 16,
M. C. Z.) Illustrated by Walcott 1881, pl. 2, fig. 16.

The sections represented by figures 1-3, 5, 6, 8-10 were made by
me and are now in the Museum of Comparative Zoology at Harvard
College, Cambridge, Massachusetts. The specimens represented by
figs. 4 and 7 are in the United States National Museum.

The sections are of trilobites from the Ordovician: upper portion
of the Trenton limestone; 1 mile (1.6 km.) east of the middle fall
of Trenton Falls, on the West Canada Creek, in the town of
Russia, Herkimer County, New York.

452 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION ‘OF PLATE 103

PAGE
Tsotelus gigas DeKay:...5:s% os oneness oto oe ee eee Oe ee 452
Fic. 1. (4.5) Transverse thoracic section cutting across the coxopo-
dite of a ventral limb. (Slide No. 19, M. C. Z.)
2. (4.5) Section cutting across the coxopodites and the an-
terior limbs beneath the pygidium. (Slide No. 226, M.
CrZ5)
Ceraurus pleurexanthemus Green. «9.254242 424s eee 304-412

Fic. 3. (<4.2.) Transverse section of the cephalon on the line of the
eyes. (Slide No. 94, M. C. Z.)

4. (12.) Transverse section cutting across the articular exten-
sion of the mesotergite of a thoracic segment. See fig. 1,
pl.95.. (Slide No. 27, M: C7 Z.)

5. (6.2) Median longitudinal section of cephalon and hypo-
stoma. (Slide No. 102, M. C. Z.)

6. (X5.) Longitudinal section cutting a little obliquely through
the cephalon and hypostoma. (Slide No. 174, M. C. Z.)

7. (4.2) Four ventral thoracic limbs cut across so as to show
the attachment of the shaft of the exopodite to the coxopo-
dites. There is also a suggestion that the parts about the
mouth have been pushed forward above the hypostoma.
(Slide No. 168, M. C. Z.)

8. (3.5) Longitudinal section through the limbs beneath the
cephalon and anterior portion of the thorax. (Slide No. 108,
MEN C@aZa)

9. (3.5) Longitudinal section cutting the outer part of the
axial lobe of the pygidium and posterior portion of the
thorax so as to show a section of the proximal joints of
the limbs beneath the pygidium. This section was figured
by Walcott in 1881, pl. 2, fig. 8. (Slide No. 18, M. C. Z.)

11. (X 16.) Longitudinal section of the proximal portion of the
endopodite shown in fig. 4, pl. 98, which cuts across the fine
spines along the ventral margin. Compare these with
spines of the endopodites of Neolenus, pl. 93, fig. 2. (Slide
INO MEL2 Oe Ne Gans)

Calymene senaria Conrad: - 2. .«.0s22h<2)scewonseaeee eee 394-412
Fic. 10. (X 16.) Longitudinal section of a thoracic limb with endo-
podite and fragments of exopodites. The spines on the ven-
tral margin of the proximal joint are of interest for com-
paring with those of Ceraurus, fig. 11. A diagrammatic
drawing of this section is given by Raymond, p. 79, to illus-
trate the alimentary canal and the infolding of the dorsal
test at the dorsal furrow which he identifies as an appendi-
fer. (Slide No. 153, M. C. Z.) See fig. 5, pl. 08.

(x 5.) Longitudinal section of an enrolled trilobite in which
the exopodites have been displaced and cut across at vary-
ing angles so as to show the almost round transverse section
with a dark spot indicating that the muddy matrix had been
forced into some of the joints of the endopodite. (Slide
INoOm200 NiesG eZ)

14. (4.2) Transverse section of an enrolled specimen cutting
obliquely through the head, hypostoma and almost verti-
cally through a thoracic segment and the articular extension
of a mesotergite of another segment which forms a narrow
dark crescent in the axial lobe. The important feature of
the section is the series of round and broadly oval sections
of the thoracic endopodites. Faint traces of exopodites
occur in the lower portion of the figure. (Slide No. 20, M.
C. Z.) Illustrated by Walcott 1881, pl. 2, fig. ro.

=
bo

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 108

SECTIONS OF TRILOBITES

“NI

NO. 7 NOTES ON STRUCTURE OF NEOLENUS 453

PAGE
Fic. 15. (X7.) Longitudinal section cutting across seven displaced
thoracic endopodites. The four posterior have indications
of joints and fine spines at the distal end of each. A frag-
ment of the dorsal test of the pygidium is cut across in
the lower left corner. (Slide No. 63381, U. S. N. M.)

(AOULVICICEINE CRU COCL SUC y seers ete ee ere ies eis he ees Tale led wale lave Kee) aya one) sPoletaiave 453
Fic. 13. (5.5) Longitudinal section similar to that represented by
fig. 12, to illustrate the similarity of the endopodites of this
species from Ohio with the Central New York species.
(Slide No. 68382, U. S. N. M.)

The sections represented by figures I-15 were made by me and are
now in the Museum of Comparative Zoology at Harvard College,
Cambridge, Massachusetts, with the exception of fig. 13.

The sections are of trilobites trom the Ordovician: upper portion
of the Trenton limestone; 1 mile (1.6 km.) east of the middle fall
of Trenton Falls, on the West Canada Creek, in the town of Russia,
Herkimer County, New York, with the exception of fig. 13 which
is from the Cincinnatian rocks, Marysville formation, Cincinnati,

Ohio.

454 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 104
PAGE
Ceraurus. pleureranihemus Green... o.<-. ses ee 3904-412
Fic. 1. (X6.) Transverse section of the thorax. See figs. 2 and 3.
(Slide: Wo: 21, MG Z.)

2. (x 18.) Left side of fig. 1 enlarged to show elongate epipo-
dite, fragment of coxopodite, and spines on a joint of the
endopodite. (Slide No. 211, M. C. Z.)

3. (xX 18.) Right side of fig. 1 enlarged to show proximal joints
of an epipodite and its position in relation to the coxopodite.
See fig.2) also pl. 07, figs: 1, 3,6. (Slide No. 20, Me Gaz»

4. (xX 16.) Enlargement of five joints of an endopodite, a frag-
ment of a spiral arm of an exopodite and two elongate epi-
podites. (Slide No. 111, M. C. Z.)

This slide was figured by Walcott 1881, pl. 11, fig. 2, and in 1918,
pl. 27, fig. 1. Two more joints are shown in the endopodite of the
latter figure but they are too faint to photograph clearly, and as
there is a slight gap betwen the fifth joint of fig. 4 and these faint
joints, no attempt is made to show them in fig. 4.

5. (X6.) Transverse section cutting down through the cephalon
and hypostoma. The interesting feature is the two round
dark spots just beneath the dorsal test with a projection on
the outer upper side that curves inward almost around a
dot of white calcite; all around the edges of the dark spots
minute short spines appear to project into the calcite;
there is a confused cellular structure between the two spots
that may represent hepatic ceca, and a small circular ring
above may indicate the heart; the dark spots evidently
represent a bilateral structure within the head. (Slide No.
68386, U. S. N. M.)

IP PUCNGIS. (COCCI FUGUES. IDNWOYNS o donkeacccoouecodauesdsavdcocsuocub uence: 451
Fic. 6. ( 10.) Transverse section of an enrolled specimen cutting
the cephalon, hypostoma and some of the ventral appendages.
(Slide No. 230, M. C. Z.)

7. (xX 25.) Enlargement of right side of fig. 6 to show the out-
line of endopodites, faint traces of exopodites one of which
suggests a spiral structure, and transverse section of several
endopodites in the lower right side of the slide. The exopo-
dites are too faint to photograph clearly. (Slide No. 230,
MEG)

8. (X15.) Transverse section cutting an hypostoma about mid-
way of its length. (Slide No. 68383, U. S. N. M.)

9. (xX 18.) Transverse section cutting the cephalon on the line
of the eyes and the hypostoma nearer its posterior end than
in fig. 8. There are traces of two cephalic limbs on each
side and above the hypostoma. (Slide No. 68384, U. S.
N.

10. (x 40.) Enlargement of the section of the eye on the right
side of fig. 9. The corneal lenses are finely shown but the
outer cornea has been destroyed.

Ir. (> 18.) Longitudinal section of the axial lobe cutting the
cephalon, thorax and pygidium. The traces of the bases of
the thoracic limbs are similar to those of Calymene. See
pl. 101. (Slide No. 68385, U. S. N. M.)

The specimens illustrated by figs. I-11 are from the Ordovician:
upper portion of the Trenton limestone; 1 mile (1.6 km.) east of
the middle fall of Trenton Falls, on the West Canada Creek, in
the town of Russia, Herkimer County, New York.

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SNOILO37709 SNOANVIIZOSIN NVINOSHLINS

NOS 7 NOTES ON STRUCTURE OF NEOLENUS 455

PAGE
Ree MUS UCI GREG ise 5 ho) 1, cets ok ee ci heb ee. 413-415
Fig. 12. (X12), 12a (X7). Two photographs of one of the Beecher
specimens showing the side view of the broad joints of
five thoracic endopodites and a view of the narrow ventral
margin of the same. This specimen gives a very clear idea
of the form of the joints of some of the thoracic endopo-
dites. (Specimen No, 222, Peabody Museum.) This speci-
men is illustrated by Raymond, pl. 4, fig. 5.

13. (X 10.) Photograph of ventral view of two endopodites with
accompanying exopodites coming from beneath them. The
four distal joints of the endopodites are lying with flat
side up while the ischiopodite and basipodite and the coxo-
podite show their narrow ventral edges. (See description
of specimen No. 218, Peabody Museum, in the text.)

This specimen is reproduced by Raymond, pl. 6, fig. 3, and a dia-

grammatic figure p. 157, fig. 43.

14. (X7.) <A photograph of Beecher type specimen showing the
“apodemes ” of the ventral integument. (Specimen No.
219, Peabody Museum.)

This specimen is reproduced by Raymond, pl. 2, fig. 6.

15. (X10.) A photograph of Beecher type specimen of cephalic
limbs; this is one of the finest illustration of the gnathites
worked out by Beecher. (Specimen No. 211, Peabody
Museum. )

A photograph of this specimen is reproduced by Raymond, pl. 2,

fig: 5)

The specimens illustrated by figs. 12-15 are from locality 373,

Ordovician: Utica shale; 3 miles (4.8 km.) north of Rome, Oneida

County, New York.

456 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION: OF PEA res

Calymene senarid Green... 62 5, on. Sc nase eee aes Se ee eee 306
Fic. 1. (x 8.) Longitudinal section of the axial lobe that is slightly
oblique to the median line; it cuts across the base of some
of the coxopodites of the anterior thoracic limbs, and pos-
teriorly the thickened sternites of the ventral integument.
The section is described in detail in the text. (Slide No. 34,
M. C. Z. Illustrated by Walcott 1881, pl. 5, fig. 2, and again
in 1918, pl. 28, fig. 8.) On fig. 6 of pl. 5, 1881, the line c-c
represents the location of this section across the trilobite.
2. (x 8.) Opposite side of the opaque slide of fig. 1. This cuts
the axial lobe a short distance from the dorsal furrow of
the test and like fig. 1 is slightly oblique to the median line
of the lobe, with the result that the proximal joints of the
posterior thoracic limbs are difficult to interpret. (Slide
No, 34, M. C. Z. Illustrated by Walcott 1881, pl. 5, fig. 1.)
On this the line a-a’ of fig. 6 represents the location of this
section across the trilobite.

The sections represented by figures t and 2 were made by me and
are now in the Museum of Comparative Zoology at Harvard Col-
lege, Cambridge, Massachusetts.

The sections are of trilobites from the Ordovician: upper por-
tion of the Trenton limestone; 1 mile (1.6 km.) east of the middle
fall of Trenton Falls, on the West Canada Creek, in the town of
Russia, Herkimer County, New York.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL- 67, NO. 7, PL. 105

SECTIONS OF TRILOBITES

PAGE

PN DIT TVSOINTG | SUNGET OMe AeA oe ets ae rae ie TO Se SeUreaert) ee ee 426
ALIICEN SSE ie CHI ADR ec as ee ea 1 ae eR eS 25
SPUD (DIBINS a cretion eae Ge eT aol a on Se area ene oan eed 415
Praspinestasmanie Ge. NM. WhOMmsOi. 5+. ode las oss bce bs Chat benln 303
AUBESS ~ 5 Sos thesic cicachtllt 8 an ee np Ree go Ee a a a 371, 386, 393
tachment on ventral limbs to dorsal test. ......22+2+25+e.aceces.nteaee 382
ASS Leia he Rem ne, sy Siteeas, ees ae oes RNa naee 366, 368, 369, 371, 380, 3890, 435
Beecher, Dr. Charles E.........376, 378, 379, 306, 414, 415, 416, 417, 424, 420
LEIA TI QOS 6 8b cot ge ae Ee Tee ee 420, 427
(Caley, 1D eS, No ae ec ee a a pe Uae Sr 376, 380, 419, 420
Calymene and Ceraurus, jointed epipodites of.............0--ceeeecccees 419
SEMUICURE MONE OPO MIteMOle. = ste sree chore ar neue eatin nae esln eE 412
Calymene meek: Foerste, figured, pl. 103, fig. 13........0..<0e2e00000 000s 453
Calymene senaria Conrad............ 304-400, 410, 411, 412, 419, 420, 421, 422
PIAMECMMIOMG ES a5 te: SR Siac ag oo Sos ace ealad hetee ae ae MS 434
PIMOS MISS eI selO OMG MO eaih hace heer alaicyce Ocean ears 439

PSO ONTOS Wi Ti= 3 ere ey ence cer etter sucnes aie aisin MGS goa ai cares NEA, te EPA 440

DL NO et OER OE ee ae ar Rn ey a 442

fBoT Las OLSVES Ke wd le cay ER hcl oe Ne a dk 445

PROG FT Ie SE 25 An TO AS srasare ahs is) soto daw gees aime Dake 446

(DILS NOC) St aS ae RS We va eae ee rt oe nee ene re Se 448

DID GLADE ine Gta (ie 2 i Sorted tr ara i eg PRES A ALS Ro 450

PI RRUOR RMS StesllOyr U2. SUAS Sopa tices Bice ae eos ae eein neo eee 452

PL MeLOS MAORI nh Ne conch REN cya ees tiled st eee ve neta aces nd 453

RO CITE M Oa ecerccoye ates Sel cence cies sce Teesa to nee eto aes Seo Ree 409

errs Alia GIVI EMOTES OI: fae ajeca 2.800 oh Woe wad 5 crane bine Ore dade Wie asec 304
SIRTCeUneLOt CxO POMIbevOr sa) cae sc tis «ai mie oes Semis ane o sleavasre hero hie see 412
Ceraurus pleurexanthemus Green. ...400-407, 411, 412, 419, 420, 421, 422, 425
(FiRREUTeCaCG Lea) to) Looe ee USE a eta ee 434
DIOS MS RLS P07 x tire ala 3. eek tale ate avin Sarte me eee 438

DML COCO OVE We cree tes Re A Alc NIN Rey ee i 440

Plea arsenic Or aan cats ene eM ar cra wi Ate oh ies ter AR Scote 442

Pa Dee Oop ONL S sek SM eo ES n cen Sve og Steyt «eae anaptuega ts Stace tense Sanieieds 5 444

PERO) cia eS take 3k Ota ce ets deh, wea ucusiayere mera eae Sear wwe ara See AS 446

‘DL; sRCOLO VPI Res A GeeAIE Ole [ener eterno RNG IEE ono TELS Clee Soe mare 448

TU RETO Tay, LO! age sce settee eo ctecls hie es te Foes. «stare oR alle tums ra cree 450

POO eS TOL 4?.cslavcies shi" Ae trae are aed CR era a ces 451

Pale LOS em eaSe OSE Ole WT G5 x55. 0:5- See, hh aielwerny meet aE RE RURS, Ouch ts oPeead 452

TIIMEDOA MISS ESSN SOAS Zu, Sistah chaps ee eee Geichens Aun vee 454

He Pam Te, coo 5 Oe) atta aucr cia o-2 eA a oan sees eee ates 384

SET SOLAR VE “ONS. gs PEAR enat es ee oreo ae ee RE See 412

INDEX

PAGE
@oxopodites andstralls onitmlobitesmemer ane erence bee eee cee 420
CGryptontinues: tessalatice Greenman terrier eerie eee 386, 426
Glimacea < sda tetthn Satie eae corso GR OO Oni en Cine eee 370
Gy OWS es hs Sons NESTE oe Oe OT MOE BO OCC Ce 306, 418
TO DAS CWS! — oi susslstere dtton Ibe yet otek RIES ce vd Ne) on Se Ee ee eee 431
DIPOLES <a cre.5/alaii'e: ovate eicreics Sh aeenehel syst Cnet oO Deere aL eaSte eee 366, 371, 380
Epipodite, exopodite and, structure of the... 5.4. sa... eee 369
COMPATISONCOL Fea sos ac vestgae os bu Daca oe Sarasa oa eee er 372
Bxopoditeyand epipoditesstnuctine voi theasene eerie ar eee cee eee 369
COMPARISON OF cs i.g:e4o5 wrt: deo ee eS om eau ele eee tOn ate Cee 372
Exopoditeor Galynvenes. =o nes oncicdete eceret emer iera co ences ae eee 409
Exopodite Of CeraurUs, oot ws bacco adhe. o) Ree eas ee 412
Exopodite Of D7tartHpus: oc. ccnno wre aoe oie nasents dk te ee eee 413
IEXOPOCIteS seiko ce ee eas oe ae ee ea ee ra ree 366, 370, 375,423
Glee RARER ee AGREE Rca na TPR eee tren pn is, mM rr AR Ma Son ono 0 427
Hepatic elands scat. wotiiie ak ae caries cialis sronsoonhy sere nisin ery ere aah eee 426
Folia: rower NValeott~<.62c22den sete mis oe eines Sys. oe 431
IntermaloreanS: cogs a. ce soe eats 00 cents rclae, store eketieicners on ee eee 425
PS OLCTAUS tsar ro Site oe ee he Sone Se Oe eee 385, 386
lisovelusi gigas.) eiitayanietneds plelO3)iese le Zrii ieee eee ene 452
TsoveluMsmmanimu's ACOCKE a. cn grr. ae oe oe Oe a ae eee 429, 430
inesley ors Wen Simeees ss, ais ates oe a ok Siw wee sch nhs cra vce eee 427
Limbs, thoracic, of Neolcnus, Ceraurus, Calymene and Triarthrus........ 420
Lambsom life, position Oh. .%.2. 042 deus ven ees oo mone one oe eR eee 386
1 UE OOM TS Rak EE toh eT oa Re Ah TR Ss RU rah 385, 386, 427, 428
Marrella vexopodites 108 Asc doneavaw dado tas oe ce ere aus
Marrellaysplendews NV alcott, nuic ste set cena a eee eee 275. 27 On AligeeAeu
Mesonactsqulberta fatia cx Bce5 bak oo wvge ee er ee 431
MIS CHO DUS CLES aie scares seal oe al eee eee ehh Oe Ce ee A431
Mins Gtila tine s.o2 10.0% Sate nas Wels aio seep eau sade se Oe 42
INGO RUG Mere ct.S rst oye aeate wet eho ths oP tn ee ese NAR Ce alg 426, 427
Neolenus: serratus Rominger 22.02 os005 sons 0. 22 ose 369-375, 380-394, 420, 421
figured) plo ifies..a,.2cs..es4- RT eR OER gine oc Oo 6 434
ple O25 fies. 1-01 lees A? Sea. Sate aoc ase 435
DIAOBENMI OS TL he tee. Renda kta be otha aan 5 ae ee 436
DU Qa TSE To ya SF sexe gere dc have ancients eke Se aa aa ee 437
EGC EIS TY SRM 5 LO eek Mt By, ay Sua hi ern ee eer 371
Ve LF dc? vacteteg Ye tor ak meta he mr oteraeand: Soe Ra ee 372
WIG. AUD: hs, Serhan edad Bee nares aR ae ee 373
TI'S WA) SL a om cotaren nasfeed apnea meme kolereiahions Ok care tots dace eee 375
1D oa Roe Ree ee ee Ce RRR ER A AL Gro Wana 6 383

INDEX

Neolenus serratus—Continued. PAGE
individual specimens Of, NOteS: ON. «..5.<..c022 ace +e vecceeeassced 387
Hoteswonmventraluappendaces Ol amscer serene eee oe cee nee 366
REStObAMOMrOn Ventral, SimAC@ Ol... <..% os wei ccs seca tev iesaeeere 302

LN BEV D1 HETRLEAS TANG EN (C0) 5 ee ea a Sos eon a ee an 431

Oldest known trilobite fauna, note on occurrence of.............0...-0 eee 431

LOU EUIVELINPES GUGINO O71 gs hee a NORE UTTER gc to coe eee OD 431

Pen tel AuineniistaCeat-lel: 4. cates 4 Shaca sah, Oe he oe a OSE eo ee oa koe 430

PIEMED THIER ie Rioee AS Se ORE LY ee PRCT CRE OT EG Oe ean a a 431

EV SitiaieAdopodmuesrOr PATtNTUS -n. v8 ces cach ue dos mas cs Uelddescuwe oe 415

ES eAUatee tise ot aie S WAMU. > s.2c-- 5a Ge oe oiaG wee e oferases ah alns,dalbo ae Gu a2 428

Raymond, Dr. Percy E.... .378, 379, 380, 382, 384, 387, 388, 380, 413, 415, 424,
425, 420, 430.

PGE QAP CLN LMS TOV Oy 1 a A Re een Le eee ee At ne Ae rr 379
INiedematit aeidolply. oa.) .). vierncd ecm sees cane pees 366, 368, 360, 371, 380, 380
Schinehenta Di @hiarless-cy4c tes. * aces ackin came mie Ge ome ee 366, 379, 380, 416
Bie OMEN EP CGLINS <hr aS. CEI RT SL ghd ican ere eh eas cle ee i Sn 420
SyPUMPGiL RESRV IVE WEES Aes Steere kei SR oA gee RI Ae ge oe Gna eenint 407
Structure of exopodite of Calymene and Ceraurus... 00... 00s. cece cee 412
SIM em eM ciinvanlO LOS meaner. tics de Seed tllerc cto arn cae soriatas wert e Sta-a Mamie crobeae BUG,
Ral SaOt crilopites, COXOPOGItES ANG « «c/a cice,c/ se o.5\bu/ore wie sieic. + wisidiele,c.cee ann ae 429
Wigner ins becky GreeMm: o's... ce. ssc se oa « AII, 413, 416-417, 420, 421, 422, 423
IAPEAE CCG DLL Os 84 Ft alshge0 nem ga Me, Pay 439
PIRRTOM BOS ERTS cece ete oP AE ey aR eats ooo Nar eik 455

GESIE HIVES. TOS TNO ergy oe Scien Ot het acer eer aa cee OR All

LIES, Pali Sees eka tecee Mt NGL RN PIAA a tS RCE PETE RE eae ee 421
te Be eee epee Asan hs EN er ae PM cr no aty La Re 2 423

Siral o babes. tmiEbIes OL LUE. ceisne a asios eas sa ees Rode Gants A Caaea caw eens 37
Trinucleus concentricus Eaton, figured, pl. 104, figs. 6-11................. 454
(CINITE rel ns ID ies, 2] ENG) ese rrr tay eee me eee ear 366, 368, 369, 371, 380, 381

‘\Y/SEah HTS a SER SEN AN ty cee, a ee gk MR St hg ec a 387

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 8

CAMBRIAN
GEOLOGY AND PALEONTOLOGY

No. 8. NOMENCLATURE OF SOME POST CAMBRIAN
AND CAMBRIAN CORDILLERAN
FORMATIONS (2)

BY
CHARLES D. WALCOTT

(PUBLICATION 2673)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MARGH 5, 1923

TBe Lord Galtimore Mrees

BALTIMORE, MD., U. S. A.

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CAMBRIAN GEOLOGY AND PALEONTOLOGY

NO. 8—NOMENCLATURE OF SOME POST CAMBRIAN
AND CAMBRIAN CORDILLERAN
FORMATIONS (2)

By CHARLES, D: “WALCOTT

CONTENTS PAGE
NBME RY ETAT EEN ROT om, 5 A NB an Bi Re ee PR REO OSA ear eye ee ae 457
ots antec ake aStig Chetan ta cyec cate Sete hourd Soe Sue Sire hee ARS Setwen s 3 es 458
AOC antici Otstrl Ail Otte W..chorenee otc. op, 4 sation onckees Cle eee ae eae cer ore Oo auels 458
Gilscier bailkew GMC RG Ra Seep eee Pree RR EA ica Caer ana ic Bette (ra iene ea! 459
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IMG Uinta Vid SOD ee sean ar oees, ee eeesme atic wae teeters ioe alain 464
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(ODS ETRVaIERETISE og hoes ae ome Eta DU olb hece GIES SiR SN ee 475
NOMENCLATURE

A number of new names have been given to sedimentary forma-
tions in connection with the study of sections of pre-Devonian for-
mations in the Canadian Cordilleran trough of Alberta and British
Columbia. One of these occurs in the Robson Peak ‘district and
others in the area about the headwaters of the Saskatchewan River,
Alberta and elsewhere in the Cordillera of western America.

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 8
¢ 457

458 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

ROBSON PEAK DISTRICT

In my brief paper on the Cambrian formations of the Robson Peak
District * the upper 3000 feet (914.4 m.) of the section in the Robson
Peak massif was included under the Ordovician system in the Robson
formation. There was not much opportunity to get at this portion
of this section on Robson Peak and no detailed section of the forma-
tion was made or fossils systematically collected from it except near
its base at Billings Butte.” During the field work of the past four
years a formation has been delimited between the Upper Cambrian
Lyell formation and the Ordovician Sarbach formation that was
found to be characterized by a fauna, one zone of which could be
compared with the fauna of the lower portion of the Robson forma-
tion. This led to a review that resulted in the decision to arbitrarily
delimit the lower porton of the Robson formation as a distinct for-
mation and name it the Chushina formation.

CHUSHINA FORMATION
(OZARKIAN, LOWER)

Locality—North slopes of Phillips and Lynx mountains * and Bill-
ings Butte, Robson Park, British Columbia, Canada.

Derivation—From Chushina glacier.

Character.—Bluish gray, thin-bedded limestones.

Thickness——The base of the formation is placed at the lowest
layer of rock containing the Hungia* fauna (locality 61q), although
it is highly probable that the upper portion of the Lynx“ limestones
may contain a fauna that will include it in the Chushina formation.
The upper limit is arbitrarily placed 1500 feet (457.2m.) above
where the shale and thin-bedded limestones give way to massive beds
of limestone forming the main mass of the upper portion of Robson
Peak.

Organic remains—The fauna at Billings Butte includes several
genera that may be referred to as typically Lower Ozarkian and
post-Cambrian, 7. e., Orthoceras, Apatocephalus, Hungia, Symphy-
surina.

* Smithsonian Misc. Coll., Vol. 57, No. 12, 1913, pp. 336-337.
7 Loc. cit., p. 336.

*Loc. cit.) pl. 58, fie. 2s pl. 50, fig: 2:

“Loe. cit;, ipl $77 he.e:

= Loc: cit., D1 330:

oe. cit.,104997,

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 459

GLACIER LAKE DISTRICT

In a preliminary outline of the Glacier Lake section,’ which is
about 48 miles (77.2 km.) northwest of Lake Louise Station on the
Canadian Pacific Railway, Alberta, Canada, names are proposed
for the following pre-Devonian formations:

SARBACH FORMATION
(ORDOVICIAN )

Type locality—Upper gray limestones and shales forming cliffs
beneath the dark Devonian limestone on Mount Sarbach and the
eastern and northern ridges of Mounts Outram and Forbes above
Glacier Lake, which is about 48 miles (77.2 km.) northwest of Lake
Louise Station on the Canadian Pacific Railway, Alberta, Canada.

Derivation—From Mount Sarbach (10,700 feet, 3261.3 m.) which
is directly east of the Glacier Lake section.

Character—Thick-bedded 6 inches (15.2 cm.) to 16 inches
(40.6 cm.), gray limestones, 700 feet (213.3 m.), and argillaceous
shales with thin, irregular layers of limestone, 420 feet (128 m.).

Thickness——Above Mons Glacier at head of Glacier Lake canyon
valley 1120 feet (341.3 m.), of which the upper 700 feet (213.3 m.)
is estimated.

Organic remains—Lower Ordovician (Canadian).

Observation —The Sarbach formation was recognized in the Clear-
water section 33 miles (53.1 km.) southeast of Glacier Lake, where
it has a thickness of 1172 feet (357.2 m.) and a well marked fauna
at several horizons.

At Fossil Mountain, 18 miles (28.9 km.) southeast of the Clear-
water section, the Sarbach has a thickness of 1090 feet (332.2 m.),
and at Ranger Canyon in the Sawback Range 21 miles (33.8 km.)
southwest of Fossil Mountain there is no trace of the Sarbach, the
Devonian being separated from the subjacent Mons formation by a
few feet of dark shale of undetermined age.

Mons ForMATION
(OZARKIAN, LOWER)

Type locality—Alternations of calcareous shale forming steep
and ragged slopes near the lower and southeast side of Mons glacier
near the base of a northwest ridge extending down from Mount

1 Smithsonian Misc. Coll., Vol. 72, No. 1, 1920, p. I5.

460 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Forbes. About 48 miles (77.2 km.) northwest of Lake Louise Sta-
tion on the Canadian Pacific Railway, Alberta, Canada.

Derivation—From Mons Peak, 10,114 feet (3082.7 m.), and Mons
Glacier, ;

Character—Massive beds of calcareous shale with intercalated lay-
ers of gray limestone above with a massive-bedded dull gray lime-
stone and calcareous shale below. ~

Thickness —In the Glacier Lake section 1480 feet (451.1 m.),
made up of calcareous shale 235 feet (71.6 m.), massive gray lime-
stone 740 feet (225.5 m.), and calcareous shale below 505 feet
(153.9 m.) thick. Thirty-three miles (53.1 km.) to the southeast, at
the head of the Clearwater River, the Mons has a thickness of 1414
feet (430.9 m.), and at Ranger Canyon, 72 miles (115.8 km.) south-
east from Glacier Lake, it 1s 1390 feet (423.6 m.) thick. It is absent
in the section of the Rocky Mountains front at Ghost River 24 miles
(38.6 km.) east of Ranger Canyon.

Organic remains—A_ post-Cambrian pre-Ordovician fauna of
Lower Ozarkian age.

Observations—The Mons formation in all known localities is
directly and, as far as known, conformable superjacent to a series of
massive layers, 10 inches to 60 inches (25.4 cm. to 152.4 cm.), of
magnesian limestone averaging over 1000 feet (304.8 m.) in thick-
ness of the Upper Cambrian Lyell formation.

LYELL FORMATION
(CAMBRIAN, UPPER)

Type locality—Massive-bedded gray and oolitic limestone at head
of Glacier Lake canyon valley about 2 miles (3.2 km.) above head
of lake and about 48 miles (77.2 km.) northwest of Lake Louise
Station on the Canadian Pacific Railway, Alberta, Canada.

Derivation—From Mount Lyell, 11495 feet (3505.6 m.), on the
Continental Divide northwest of Glacier Lake. The Southeast Lyell
glacier terminates at the head of Glacier Lake canyon valley.

Character—Massive-bedded cliff forming rough weathering mag-
nesian limestone forms the upper portion of the formation, with
thinner-bedded gray and oolitic limestones beneath.

Thickness —At the type locality in Glacier Lake canyon valley the
upper magnesian beds have a thickness of 1270 feet (387.1 m.) sub-
jacent to which the thick- and thin-bedded gray limestones extend
down 430 feet (131 m.) a total of 1700 feet (518.1 m.) for the
formation. Thirty-three miles (53.1 km.) to the southeast at the

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 401

head of the Clearwater River it has a thickness of over 1700 feet
(518.1 m.), and at Ranger Canyon in the Sawback range 72 miles
(115.8 km.) southeast from Glacier Lake, the great upper limestone
is 1325 feet (403.8 m.) thick and the lower beds 335 feet (102.1 m.).

Organic remains—An Upper Cambrian fauna is fairly well devel-
oped in the lower oolitic limestones.

Observations—The Lyell formation corresponds in stratigraphic
position to the Ottertail formation of the Kicking Horse River sec-
tion southwest of Field, British Columbia.

SULLIVAN FORMATION
(CAMBRIAN, UPPER)

Type locality—Gray limestone above with arenaceous shale and
interbedded limestone on the north side of Glacier Lake canyon valley
and the south cliffs and slopes of Sullivan Peak about a mile east of
the foot of Southeast Lyell glacier. Glacier Lake is about 48 miles
(77.2 km.) northwest of Lake Louise Station on the Canadian Pacific
Railway, Alberta, Canada.

Derivation——From Sullivan Peak, 7858 feet (2395 m.).

Character.—Hard, gray, rather thin-bedded semicrystalline lime-
stone above, with arenaceous shales predominating below. The domi-
nant feature is the development of arenaceous shales.

Thickness.—At the type locality in Glacier Lake canyon the upper
limestone has a thickness of 325 feet (99 m.). The arenaceous shales
and interbedded limestones continue down for 1115 feet (339.8 m.),
making a total thickness of 1440 feet (438.9 m.).

Organic remains——Upper Cambrian fauna of about the horizon
of the Eau Claire formation of the northern Mississippi valley section.

Observations—The Sullivan formation is strongly developed in
the vicinity of Thompson Pass, 33 miles (53.1 km.) northwest of
Glacier Lake, and it is present in part in the Ranger canyon section of
the Sawback range.

ARCTOMYS FORMATION
(CAMBRIAN, UPPER)

Type locality —A bluish-gray laminated limestone superjacent to a
series of siliceous shales on the lower, southern slope of Sullivan
Peak above Glacier Lake about a mile east of the foot of Southeast
Lyell glacier. Glacier Lake is about 48 miles (77.2 km.) northwest
of Lake Louise Station on the Canadian Pacific Railway, Alberta,
Canada.

462 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Derivation—From Arctomys Peak (9162’ (2792.5 m.)) which is
8 miles (12.8 km.) east-southeast of Mount Lyell, and above the head
of Southeast Lyell glacier.

Character.—Bluish-gray irregularly laminated cliff-forming lime-
stones which are more or less magnesian in some layers. This lime-
stone is underlain by a series of arenaceous and silicious shales with
bands of hard, finely laminated, dove colored limestone.

Thickness——Upper cliff-forming limestone 520 feet (158.5 m.).
The siliceous shales and limestone below have a thickness of 866 feet
(263.9 m.) which gives 1386 feet (422.4 m.) for the formation.

Organic remains.—The character of the sedimentation appears to
have been unfavorable for the presence and preservation of vegetable
and animal life. The few fossils found indicate the Upper Cambrian
fauna.

Observations—The Arctomys formation in the Siffleur River sec-
tion 25 miles (40.2 km.) east of Glacier Lake has a thickness of 725
feet (221 m.) and appears to have been a shallow water and prob-
ably a brackish water deposit. It is separated from the subjacent
Murchison formation by a great disconformity resulting from the
non-deposition of the Eldon formation, which has a thickness of 2728
feet (831.5 m.) on Mount Bosworth, 37 miles (59.5 km.) to the south.

MurcHISoN FORMATION
(CAMBRIAN, MIDDLE)

Type locality —Thin-bedded bluish-black limestones in cliffs on
southwest side of Siffleur River, 3.5 miles (5.6 km.) from Saskatche-
wan River and 40 miles (64.3 km.) north, 12° west, of Lake Louise
Station on the Canadian Pacific Railway, Alberta, Canada.

Derivation—From Mount Murchison, which is about 8 miles
(12.9 km.) west of the Siffleur section.

Character —Thin-bedded, hard bluish-black and gray limestones.

Thickness —On the Siffleur the Murchison has a thickness of 497
feet (151.5 m.). At Glacier Lake 220 feet (67.1 m.) of the upper
portion of the formation is exposed.

Organic remains.—A few Middle Cambrian species of the Stephen
fauna.

Observations —The Murchison occupies the stratigraphic position
of the Stephen formation of the Kicking Horse Pass section, but it is
not given that name as the contained fauna is not sufficient to closely
identify it, and in an area where non-deposition of formations occurs

no. 8 CAMBRIAN CORDILLERAN FORMATIONS 463

on such a great scale, strata separated by an interval of 38 miles
(61.1 km.) may be a portion of some unknown formation or a portion
only of the formation it most nearly resembles in that province.

KICKING HORSE CANYON
GLENOGLE FORMATION

(ORDOVICIAN )

Type locality —Glenogle Creek, Lower Kicking Horse Canyon, a
little east of Glenogle station on the Canadian Pacific Railway, British
Columbia, Canada. The section of the formation was studied by
Dr. R. G. McConnell and Dr. John A. Allan* on Glenogle Creek and
the next small creek to the west, both of which flow into the Kicking
Horse River.

Derivation From Glenogle station and creek.

Character —Argillaceous and with finely arenaceous shales, black,
brown and gray in color and more or less fissile in thick bands.

Thickness—About 1,700 feet (518 m.).

Organic remains —Lower Ordovician graptolites.

BEAVERFOOT FORMATION
(SILURIAN ?)

Type locality —Crests of Beaverfoot Range east of Columbia River
valley and south of Canadian Pacific Railway, British Columbia,
Canada.

Derivation—From Beaverfoot Range.

Character—Thick-bedded gray dolomites and quartzites, with a
few bands of interbedded arenaceous shale.

Thickness——On the northern end of the Beaverfoot Range, 800
feet (243.8 m.). To the south it thickens up to 1,850 feet (563.9 m.).

Organic remains —Silurian ? corals.

FRONT RANGE

Guost River FoRMATION

The type locality is about 51 miles (82.1 km.) west 20° north of
Calgary, Alberta, Canada, in the first small canyon south of Ghost
River canyon and opening on Ghost River as the river bends to the

* Ann. Rept. Geol. Sur. Canada (for 1886) 1887, Pt. D, pp. 22-24 D.
Geol. Sur. Can. Memoire No. 55, Geol. Ser. No. 46, 1914, p. 100.

464 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

south. At the Devil’s Gap, about 2 miles (3.2 km.) further south.
the formation dips westward and disappears 1.75 miles (2.8 km.)
east-northeast of the eastern end of Lake Minnewanka.

The formation includes 285 feet (86.8 m.) of thin-bedded and
shaly, buff colored magnesian limestones lying conformably between
the Middle Cambrian limestones beneath (Cathedral formation) and
the superjacent Devonian beds (Intermediate limestone of
McConnell). They are a very conspicuous formation on the summit
of the outer cliffs for many miles along the Rocky Mountains front
from the South Fork of Ghost River north to the Red Deer River,
and the only representative of 23,960 feet (7,303.0 m.) of strata that
occurs in the Kicking Horse Pass section, 50 to 60 miles (80.5 tc
96.6 km.) to the westward between the Cathedral limestones and the
Devonian.

The lower layers of the formation rest conformably on the Cathe-
dral limestone of the Middle Cambrian, and in fact there is almost a
gradation between the two except that the gray thin-bedded lime-
stones of the Cambrian are not repeated above in the shaly magnesian
limestones. The transition to the dark gray Devonian limestones
above is abrupt and suggests a somewhat sudden and deep depression
of the sea bed.

The interval between the Cambrian and Devonian along the line
of the present Rocky Mountains front was largely one of non-
deposition, as the evidence of erosion along the several miles of ex-
posure of the contact between the magnesian limestones of the Ghost
River formation and the Cambrian beneath and the Devonian above
on Ghost River is almost negligible.

Fauna.—No fossils or traces of life were seen in or on the rocks of
this formation.

Mount WILSON QUARTZITE

Clearwater River—At the head of the Clearwater River canyon
54 miles (86.9 km.) northwest of the Ghost River section, there
are a few layers of quartzite in the interval between the Devonian and
the subjacent Ordovician Sarbach formation. They have a maximum
thickness of 24 feet (7.3 m.) and were evidently a thin deposit of
washed sand spread unevenly over the upper surface of the Sarbach
formation.

Mount Wilson—At Mount Wilson on the north side of the Sas-
katchewan River and 84 miles (135.2 km.) northwest of the Ghost
River section, a quartzite similar to that at the head of the Clearwater
River forms a massive cliff beneath the Devonian and above the Sar-

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 465

bach formation. It is not the same lithologic formation as Ghost
River magnesian limestones, but it occupies a similar stratigraphic
position beneath the Devonian, and is a deposit in the Ghost River
interval. It is an important stratum at Mount Wilson, where it has
an estimated thickness of over 250 feet (76.2 m.) and it is prominent
in the cliffs of Mount Murchison. It is named the Mount Wilson
formation and correlated in stratigraphic position with Ghost River
formation. No fossils were found in the great piles of quartzite
blocks that had fallen from the precipitous cliffs high up on the
mountain.

This quartzite thins gradually northward on the North Fork of the
Saskatchewan River until opposite the mouth of Alexandra River
it is not over 100 feet (30.4 m.) thick, and two miles further north it
can only be distinguished by a few thick layers beneath the dark
Devonian limestone.

On the south side of Mount Wilson facing the Saskatchewan River
the quartzite caps the eastern half of the high cliffs, but it has been
removed by erosion from the western half. It occurs on the north
and west side of Mount Murchison, but it is not as thick as on Mount
Wilson, and it becomes thinner on the northeast side of Mount
Murchison.

As far as known, the Mount Wilson quartzite originally covered
an area with a major axis of about 95 miles (152 km.) in a north-
northwest by south-southeast direction, and a minor axis of 6 to 8
miles (9.6 to 12.8 km.), as indicated by known outcrops. It was
a deposit of fine white sand in the shallow sea that preceded the
Devonian coral reefs and black calcareous silt in which they were

embedded.

OCCURRENCE IN SAWBACK RANGE

On Ranger Brook in the heart of the Sawback Range, 24 miles
(38.6 km.) west of the Ghost River section, the dark fossiliferous *
Devonian limestones rest with apparent conformity on light gray
limestones of the Mons* formation of the Lower Ozarkian, and be-
neath the latter the Upper Cambrian Lyell * and upper portion of the
Sullivan “ formations, the section of which is broken by a fault that
brings the limestones beneath the Sullivan formation against the

* Noted Stromatopora, Atrypa reticularis (Linn.), and numerous poorly pre-
served corals.

* Ante, p. 459.

* Ante, p. 460.

* Ante, p. 46I.

466 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Devonian. The Mons, Lyell, and Sullivan formations have a com-
bined thickness of over 3,000 feet (914.4 m.) and do not occur be-
neath the Devonian in the Ghost River section, and the Ordovician
Sarbach formation of the Clearwater Canyon section is not present
between the Devonian and the Mons formation.

Another section on the east slope of Fossil Mountain near Baker
Lake, 20 miles (32.1 km.) north-northeast of Ranger Canyon section
and 38 miles (61.1 km.) west-northwest of Ghost River section, has
on the east and south slopes of the mountain a fine outcrop of the
lower strata of the Devonian carrying numerous fragments of
Stromatopora and corals. Beneath the Devonian there is a series of
thin layers of magnesian limestone with layers of chert one to two
inches (2.5 to 5.0 cm.) thick which may be between the layers or form
part of alayer. They are 35 feet (10.7 m.) in thickness and strongly
delimited from the dark coarse Devonian limestones above and the
light gray relatively soft Ordovician (Sarbach) limestones below by
their lithological characters, but there is no evidence of a physical
unconformity between them. They correspond in position and partly
in character to the strata of the Ghost River formation and are
without traces of fossils.

EUREKA MINING DISTRICT, NEVADA
Goopw1n ForMATION
(OZARKIAN, LOWER)

Type locality—Goodwin Canyon is northeast of the town of
Eureka, and heads in the arenaceous and calcareous shales of the
Dunderberg’ formation;* it descends over the limestones of the
Pogonip Formation to where Shadow Canyon unites with it?

Derwvation—From Goodwin Canyon in the Eureka Mining
District.

Character.
of the Dunderberg shale formation with some interbedded calcareous

The argillaceous and fine grained arenaceous shale

shale pass gradually upward into purer bluish-gray limestones dis-
tinctly bedded, which were formerly included in the lower Pogonip
formation.

Thickness—In the Eureka District section both Goodwin and
Shadow canyons cut across the Pogonip limestone which Hague esti-

* Smithsonian Misc. Coll., Vol. 53, No. 5, 1908, p. 184.
*See Atlas accompanying Geol. Eureka District, Nevada, Monogr. U. S. .
Geol. Surv., Vol. XX, 1883, Map No. 8.

no. 8 CAMBRIAN CORDILLERAN FORMATIONS , 467

mated to be 2,700 feet (822.9 m.) thick east of the Jackson mine. In
the White Pine District the Pogonip was estimated to have a thick-
ness of over 5,000 feet (1,524 m.). The portion of the Pogonip now
referred to the Goodwin formation is 1,500 feet (457.2 m.) thick.

Fauna.—At an horizon about 200 feet (60.9 m.) above the base
(locality 201a) :

Obolus (Westonia) iphis Walcott
Lingulella pogonipensis (Walcott)
Acrothele sp.

Acrotreta idahoensis Meek
Schizambon typicalis Walcott
Eoorthis hamburgensis Walcott
Syntrophia nundina Walcott
Tellinomya ? hamburgensis Walcott
Agnostus sp. ?

Apatokephalus finalis (Walcott)
Hungia eurekensis Walcott
Hungia flagricauda White

Hungia hamburgensis Walcott
Hungia inexpectans Walcott
Elrathia (?) annectans (Walcott)
Calvinella tenuisculptas Walcott
Ptychostegium cf. hecuba Walcott
Ptychostegium mecoyi Walcott
Symphysurina eurekensis Walcott
Symphysurina major Ulrich (Mss.)
Symphysurina mesleri Ulrich (Mss. )
Symphysurina spicata Ulrich ( Mss.)
Eurekia sp. undt.

The next highest well marked fauna is about 800 feet (243.8 m.)
above and contains (locality 203) :
Syntrophia nundina Walcott

Ptychostegium congeneris (Walcott )
Hystricurus tuberculatus (Walcott)

OZARKIAN

This is not the place for a discussion of the Ozarkian system of
Ulrich,’ but I wish to briefly outline it in order that the position of
the Sarceen series (p. 471) within it may be clear. As proposed,
Ozarkian included a group of formations occurring in the Ozark

*Dr. Ulrich is now making a thorough study of the stratigraphy and faunas
of the formations included by him in the system, and it is anticipated that all
available data will soon be in the process of publication.

468 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Mountains of Missouri and elsewhere, above the Upper Cambrian
and below the Canadian. Some of the sections are as follows:’

EASTERN MISSOURI

CANADIAN
Disconformity.
OZARKIAN

Gasconade. Feet Meters
Cherty dolomite: [eer 2h226 ¢ otc te ecae estas hee 265 80.8
Fauna.—Large number of gasteropods, etc.

Proctor.

Massive ibeddedudolomitesyneerer eee a ee 60 18.3

Eminence.

Light colored cherty dolomistes 7c Znarcet eer oh pines 20 200 61.0
Fauna.—Gasteropods, cephalopods, trilobites.

Disconformity.

Potosi.

Light gray to dark bluish gray massive dolomite....... 300 O1.4
Fauna.—Unknown.

Of the above, the Potosi dolomite is referred to the
Lower Ozarkian.

825 251.5

Disconformity.
In the southern Appalachians of Central Alabama, Ulrich dis-

tinguishes five formations which he includes in the Ozarkian as
follows:

CANADIAN
Disconformity.
OZARKIAN
Chepultepec. Feet Meters
Chentys macnesiumi limestones. sce einer iets 1200 365.7

Fauna.—Many species of gasteropods and cephalopods.
Ulrich states that at least ten of the species occur in
the Gasconade formation in Missouri and a number
in the Oneonta of Wisconsin, Minnesota and Iowa.
Copper Ridge.
Cherty dolomntet.,. 20+. 6. nie tice as neti’ ae stneain terse OOO 609.6
Fauna.—Fossils rare, mainly Cryptozoans.

* Data taken from Ulrich, Bull. Geol. Soc. Amer., Vol. 22, 1911, pp. 630-632,
and Vol. 24, 1913, p. 51.

Dr. Ulrich included the Roubidoux and Jefferson City formations in the
Ozarkian as published in 1911. In 1912 he referred the Jefferson City to the
Middle Canadian and the Roubidoux to the Lower Canadian in a paper not yet
published (Bull. Geol. Soc. Amer., Vol. 24, p. 51), but from which Dr. R. S.
Bassler took the data for the Ozarkian-Ordovician correlation published in
1915, Bull 92, U. S. National Museum, Vol. 2, 1915, plate 2.

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 469

Bibb dolomite. Feet Meters
NIMES ab aIMeO nC GLO Iter Macha es sare ine cee hte ote estas 500 152.4
Fauna—Unknown.

Ketono dolomite.

Gay ite GLOUMTer.6 oT okie ates oye owen ka einehinae we 6co 182.9
Fauna.—Unknown.

Briarfield dolomite.

Sitcious: biuevand) eray dolomite, 2. 5%5)..5 24026 sen ae 1250 381.0
Fauna. Unknown.

Niacin umblatekaess ta aniecic cree aatete cabbaeree beoets oe 5550 1691.6
Disconformity.
The Chepultepec and Copper Ridge formations are referred to the
Upper, and the Bibb, Ketono, and Briarfield to the Lower Ozarkian.
In the Northern Appalachians the central Pennsylvania section

includes: ‘
OZARKIAN
Feet Meters
Laval ees Glolkohiani VN ae Ree ai nae CREO Re Bae ec Ri ae eee ane 76.2
Fauna—Unknown.
Wimesimenenhy, AOlOMiMte: cents’. ale cio cucleusnciarere cicPaeree el tees ovo ne 250 76.2
(Esp s slants sce plover 1 | 1 Ane aoe RANE aia een Le as eee gt A 1750 533-4
A band of bluish black limestone named Ore Hill
contains a large Lower Ozarkian fauna that may be
compared with the lower Mons fauna of the Cordilleran
area.
Mota (\Ozarkdanias cremeeet velo at se Seam meee Ac 2250 685.8

The New York section of the Ozarkian is composed of the follow-
ing formations:

Uruestalls dolomite GLittte: Halls) soe... ooeise theese 350 106.7
Hoyt limestone with a well-marked fauna (Saratoga)...... 120 306
Theresa ‘dolomite’: .\..5.5....x. APR aas eee Sra d Pb otatcrei. fa.ciate 50 15.2
otsdame sand Stone a geste aioe ze ech ooo weer thaieeeiah 110 33-5

630 192.0

The fauna of the Hoyt limestone and upper portion of the Potsdam
sandstone is comparable with that of the lower Mons of Alberta and
the Madison sandstone of Wisconsin.

In the upper Mississippi valley area the Ozarkian is not strongly
developed :

Disconformity
Oneota dolomite
Great disconformity
Madison sandstone
Mendota dolomite
Disconformity

470 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Ulrich correlates the Oneota dolomite with the Gasconade of Mis-
souri and the Madison sandstone with the Hoyt limestone of New
York.’

Using the correlation table of Ulrich in part as modified by Bassler,
and inserting two columns to represent the sections of Alberta and
British Columbia, the table (fig. 24) presents a broad correlation of
the Ozarkian system in North America.

LOWER OZARKIAN IN ALBERTA

As my field studies progressed in western Alberta, Canada, it became
more and more evident that there was a well-defined formation be-
tween the Upper Cambrian and the pre-Devonian Ghost River interval
that was characterized by a fauna easily distinguished in its central
and upper portions from the Upper Cambrian fauna by the presence
of cephalopods, gasteropods and types of trilobites represented in the
succeeding Canadian faunas of the Ordovician. In the lower part of
the formation the fauna is predominantly Upper Cambrian, but trilo-
bites of the genera Megalaspis, Niobe ?, Asaphellus, Hungia, Symphy-
surina, midway of the Mons Formation strongly foreshadow the
change to the Ordovician fauna, and the change in sedimentation also
aids in drawing a line of demarcation between the massive Lyell lime-
stones of the Upper Cambrian, and the shales and thin-bedded lime-
stones of the Mons formation of the Lower Ozarkian.

In the Glacier Lake section the Mons formation has a thickness of
1480 feet (451.1 m.) of which the lower 505 feet (153.9 m.) is com-
posed of shales and thin-bedded limestones. Below the shales the
thick-bedded limestones of the Lyell formation extend down for
1,270 feet (387 m.) forming a bold ridge terminating in high cliffs.
Thirty-eight miles (61.1 km.) to the southeast of Glacier Lake at
the head of the Clearwater River canyon the Mons formation has
a thickness of 1,414 feet (430.9 m.) with shales and thin-bedded
limestones in the lower portion. Below there is a series of massive-
bedded magnesian limestones 910 feet (277.3 m.) in thickness of the
Lyell formation: Forty miles (64.3 km.) southeast of the Clearwater
section in the Ranger canyon section of the Sawback range, the Mons
formation is directly beneath the Devonian limestones and has a thick-
ness of 1,390 feet (423.6 m.) and a bed of thin layers of shaly lime-
stone and shale form the lower portion of the formation. This is
underlain by a series of thick-bedded arenaceous and magnesian lime-
stones of the Lyell formation with a thickness of 1,325 feet

*See Ulrich, Bull. Geol. Soc. America, Vol. 22, 1911, pp. 627-647.

}-~

:
s

aca t

CAERBRIAB-OZAREIAN-ORDOVICIAN CORRELATION TABL E.

Alberta
Saskatchewan

GENSRAL TIKES SCALE Pennsylvania Alabems Dast Missourt

Bellefonte (Pa.) | Bellefonte aol. bgt TTT TTT Powell 1e.
Shakopee
a Ce ca
aap oe) freee on | foeter HITT

See = Lae
ptetyonema bed __|repreeentees JIIIITIIIITI _—sSTTT TTT

faeeaate ol] empisene to, SPE] atte (MIU
| cree [sorrersiage( tenn. Farrer Serer ON YC UTINOHNOEATHGQNGNIZTIG
=r mssvnee nore TUTTI EEL
piven, foto we. {TMH
etonm ect TTTTITTTTUIIIIL ettecs oo | aon
piertioxa an | TTTITELIE TE | mentee a0,

a Jordan es.
o|St.Lawrenoce f.
plPranconia ss.

Central
Wisconsin

Alberta and B.C,

Sarbach

Goodeir 7?

LOWER Sarceen

Goodsir

Ottertadl,
Chancellor

Lyell

Warrior ls. Nolichucky sh.

Marysville ls.

Elvins forn.
Bonne Terre dol.

Sherbrook
Rogersville sh. |Leamotte ss. “9\Dresbach ss. aalkiver Paget
Pleasant Hill le. ojEau Claire es. Bosworth

Arotonys

< » 43 ¢ =3>
COUP TIT eiton
(IDDLE Murehison Stephen
‘i ‘dar ee Cathedral Cathedral
TTT cle
Mt. free eee Mt. Whyte
ane Weucoban free eee Piren St, Piran
Lake Lonise
TEETEEL ELL LLL tere a:

HYG) 24:

4s
ns
oy OIE ol Re te Pewee te v
My rapt! “ Ne ha rar ae lean) we
yo wey * ge? A
Creed Sha ty BW ee eivite 1 if
eae ae Wide site

fom’, bees ale ae

1
*!
“
'

yl ‘*
en coe at Sana af

i. ar ( ry
ei she an cae
pit % are! .7 ie xR

} ; i a i—any aSaks Owriast pam
i egieAihe toh ON SU SR GAD AV ee Oi alae

‘
: ‘
* ee i vs oO a)
pe? pre

f : | f poy

Sry . hee ven V a 4 A ae a A oe hn,
liar A s a Perse 5 i/4 <r ies gralak

1 , i Spbrey a Pag Pf : Py bd al ey pay eae a

Sky ‘is Pe hem ty Ue, |

q < « i

i t ! 7
f Hi i FA, eee
+ lA tie ee! or Se ried Sr teetin | gm latino ee ee Pay

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 471

(403.8 m.). About 132 miles (212.4 km.) north of the Glacier Lake
section at Mount Robson the Chushina formation has an arbitrarily
assigned thickness of 1,500 feet (457.2 m.), but neither the upper
nor lower limits have been determined.

The fauna of the Billings Butte beds of this formation:may be com-
pared to that of the lower portion of the Mons formation, but it will
be necessary to make a detailed study of the section before a close
comparison can be made between the Mons and the Chushina as my
reconnaissance of 1912 did not take in the details of the formations
above the Middle Cambrian.’

In the Kicking Horse Pass and River section the Mons formation
has not been recognized, but its stratigraphic equivalent is indicated
by the fauna in the lower portion of the Goodsir formation, which
includes :

Obolus mollisonensis Walcott
Lingulella moosensis Walcott
Lingulella sp. undt.

Agnostus sp.

Moosia degener ‘Walcott
Moosia grandis Walcott
Sodalitia canadensis Walcott
Sodalitia allani Walcott

In the absence of fossils from other horizons in the Goodsir, and
as the formation is practically a lithologic unit, I am placing the entire
series in the Ozarkian. See notes under Mons, Chushina, and Good-
win in this paper.

SARCEEN

This term is proposed as a series name to include the various for-
mations referred to the Lower Ozarkian on the North American
continent. The type formation is the Mons, which occurs in the
Rocky Mountains of western Alberta, Canada (ante, p. 459). The
correlated formations in the Cordilleran trough of the Rocky Moun-
tains are Chushina (ante, p. 458) on the north; Goodsir, at least -in
part, on the south in Canada; in the United States the St. Charles
formation of Idaho and Utah; the Red Lion formation of Montana ;
the Goodwin formation (ante, p. 466) of Nevada, and the Notch
Peak formation of Utah.

On the eastern side of the continent the most typical formations are
the Potsdam sandstone and Hoyt limestones of New York and west-
ern Vermont; the Gatesburg dolomite of central Pennsylvania, and

* Smithsonian Misc..Coll., Vol. 57, No. 12, 1913, pp. 336-337.

472 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

the “ Potosi,’ Ketona, Briarfield of Alabama. In the interior region
the Wilberns formation of Texas; the Potosi formation of Missouri,
and the Mendota, Madison and Devils Lake of Wisconsin.

Derivation.—From the Sarcee Indian tribe, which ranged in west-
ern Alberta north of the Blackfeet (Siksika) tribe and hunted up
the river valleys to the Continental Divide.

Thickness——In the Canadian Cordilleran region from 1,480 feet
(451.1 m.) Mons to 6,040 feet (1,841.0 m.) Goodsir. In northern
Utah, 1,311 feet (399.6 m.) St. Charles. In central Nevada 1,500
feet (451 m.) Goodwin formation.

In the Appalachian trough from 2,500 feet (762.0 m.) in Alabama
to 350 feet (106.7 m.) in New York.

The Lower Ozarkian in Missouri is represented in part by the
Potosi dolomite which is about 300 feet (91.4 m.) thick.

Organic remains.—The fauna of the Mons formation of Alberta
is large and varied. The following genera and species occur in the
limestones 18 feet (5.5 m.) below the summit of the formation
(locality 64p) :

Eoorthis cf. wichitaensis Walcott
Syntrophia isis Walcott

Ophileta leo Walcott
Eccyliomphalus josephus Walcott
Eccyliomphalus labeo Walcott
Bucaniella lelex Walcott
Raphistoma melius Walcott
Lophospira laodice Walcott
Hormotoma lamus Walcott
Straparollina isades Walcott
Orthoceras longus Walcott
Orthoceras robsonensis Walcott
Ptychostegium fulvia Walcott
Ptychostegium victori Walcott

At a lower zone, 60 feet (18.2 m.) below the summit of the forma-

tion the collection included (locality 66u) :
Lingulella sp. undt.
Syntrophia
Eoorthis
Ctenodonta ? lucan Walcott
Platyceras lais Walcott
Megalaspis ? eucerus Walcott
Megalaspis ? sp. undt.
Maryvillia galeria Walcott

Near the base of the Mons formation in the Glacier Lake section
the following species occur (localities 64f, 64n) :

Cystid (fragment)
Eoorthis sp. undt.

No. 8 CAMBRIAN CORDILLERAN FORMATIONS 473

Huenella sp. undt.

Scenella ?

Ptychaspis eurydice Walcott
Elvinia phyllus Walcott
Saukia ? glaucus Walcott
Obolus cf. leda Walcott 64n
Blountia sp. undt. 64n

Saukia splendens Walcott 64n

In the Clearwater canyon section 33 miles (53.1 km.) east-southeast
of the Glacier Lake section, the following genera and species occur
288 feet (87.7 m.) above the base of the Mons (locality 65y) :

Obolus sp. undt. (fragments)
Lingulella cf manticula White
Eoorthis iones Walcott
Agnostus sp.

Modocia ibicus Walcott

Hungia flacilla Walcott
Symphysurina eugenius Walcott
Acrocephalites gentius Walcott
Niobe ? nonius Walcott

Niobe ? phormis Walcott

About 100 feet (30.4 m.) from the base (locality 65w) :

Cystid (plates)

Eoorthis iones Walcott
Straparollina sp. undt.
Irvingella ? undt.

Niobe ? echides Walcott
Amphion ?? sp. undt.
Symphysurina entellus Walcott
Rogeria ? ephorus Walcott
Asaphellus euclides Walcott

In the Robson Peak section the lower fauna of the Chushina for-
mation corresponds in a general way to the lower fauna of the Mons
formation (locality 61q) :

Lingulella cf. desiderata Walcott
Lingulella ibicus Walcott

Obolus ino Walcott

Acrotreta cf. idahoensis Walcott
Acrotreta cf. sagittalis Salter
Eoorthis cf. desmopleura (Meek)
Eoorthis cf. wichitaensis Walcott
Straparollus ? lavinia Walcott
Bellerophon ? lavassa Walcott
Cyrtolites meles Walcott
Orthoceras robsonensis Walcott
Agnostus sp. undt.

474 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Menomonia gyges Walcott

Blountia galba Walcott

Cyrtometopus ? sp. undt.

Moxomia hecuba Walcott

Hystricurus gallus Walcott
Hystricurus bituberculatus (Walcott)
Apatocephalus bréggeri Walcott
Apatocephalus fronto Walcott
Hungia articauda Walcott

Hungia billingsi Walcott

Hungia flacilla Walcott

Hungia laxicauda Walcott

Hungia striata Walcott

Hungia flagricauda (White)
Ptychostegium amplum Walcott
Ptychostegium robsonensis Walcott
Ptychostegium robsonensis valaltum Walcott
Ptychostegium canadensis Walcott
Ptychostegium spinosum Walcott
Symphysurina spicata augusta Walcott
Symphysurina canadensis Walcott
Symphysurina lynxensis Walcott
Symphysurina spicata major Walcott
Symphysurina numitor Walcott
Symphysurina perola Walcott
Symphysurina spicata Walcott

The St. Charles formation of northern Utah has a large and varied
fauna. The upper zone includes (locality 185z) :

Eoorthis cf. desmopleura (Meek)
Syntrophia sp. ?

Ctenodonta cf. lucan Walcott
Bucaniella ? isades Walcott
Bucaniella ? leos Walcott
Eccyliomphalus lacidos Walcott
Straparollina milo Walcott
Ophileta leo Walcott
Raphistoma menos Walcott
Orthoceras utahensis Walcott
Endoceras sp.

Hystricurus sp. undt.

Blountia sp. undt.

Asaphus ? sp. undt.
Ptychostegium idahoensis Walcott
About 75 feet (22.8 m.) below the following species occur

(locality 54b) :
Lingulella manticula (White)
Billingsella coloradoensis Meek
Syntrophia nundina Walcott
Hungia hera Walcott

no. 8 CAMBRIAN CORDILLERAN FORMATIONS 475

Some 1,200 feet (365.8 m.) from the top, near the base of the
St. Charles, the fauna has a very strong Upper Cambrian character

(locality 4y) :

Obolus wortheni Walcott
Lingulella desiderata Walcott
Acrotreta idahoensis Walcott
Acrotreta idahoensis sulcata Walcott
Billingsella coloradoensis Meek
Agnostus a

Agnostus D

Saukia marica Walcott (54u)
Saukia oneidaensis Walcott
Elrathia lycus Walcott (541)
Elrathia sp. (54t)

Taenicephalus lycoria Walcott
Taenicephalus mutia Walcott (5a)
Maladia americana Walcott
Idahoia sp. undt. (5a)

Idahoia serapio Walcott

Idahoia licinia Walcott
Anomocare sp. undt. (54u)
Anomocarella lucius Walcott
Anomocarella macar Walcott
Anomocarella sp. undt.

Wilbernia fronto Walcott (5e)
Wilbernia (Ulmia) martha Walcott

In the Eureka District section of central Nevada, the Goodwin for-
mation (=lower 1,500 feet (457.2 m.) of the Pogonip formation of
the Fortieth Parallel Survey) carries a fauna which is partially
listed under the description of the Goodwin formation (ante, p. 466).

Observations —The preceding tentative faunal lists are given in
order that the student may have some conception of the fauna char-
acteristic of the Sarceen or Lower Ozarkian series in the Cordilleran
area. It is now planned to publish illustrations and notes on the
fauna in 1923.

The Sarceen series may be compared with the Tremadoc series of
Europe; both the Tremadoc and Sarceen series of formations are
above the typical Upper Cambrian and beneath the Ordovician ; both
series are well defined stratigraphically and by their contained faunas.

The term Sarceen if generally accepted will replace the term Sara-
togan as used by Ulrich, who used it to include the formations of
the Lower Ozarkian. Walcott * proposed Saratogan as a group term

* Bull. Geol. Soc. America, Vol. 22, 1911, pp. 332-3, 338.
? Jour. Geol., Vol. 11, 1903, pp. 318-310.

476 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

to include the Upper Cambrian formations, as at the time he consid-
ered the Potsdam sandstone and Hoyt limestone of the Saratoga
New York section to belong to the Upper Cambrian. With the refer-
ence of these formations to the Ozarkian and the fact that no
Upper Cambrian formation occurs at or near Saratoga, the name is
not appropriate for the Upper Cambrian series of formations.

It is not improbable that as the faunas are more thoroughly studied
by Dr. E. O. Ulrich, a middle division of the Ozarkian will be estab-
lished to include the Eminence and related formations.

: fata oa Je

rae .

othe et Ah Si pata ae
PACU 5 dee Gee

trys iene oT aka: Sig ie Duis oe etthg Me ine we

at ew et A ca Lea ae Bara |

ae s ot Pe it ae ay A eh Cas ats oy wie pea:

-
.

Ne 1s vs i i ark , ALR ‘e a PB ‘art iver Sie %

SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 9

CAMBRIAN
GEOLOGY AND PALEONTOLOGY
IV

No. 9.—CAMBRIAN AND OZARKIAN BRACHIOPODA,
OZARKIAN CEPHALOPODA AND NOTOSTRACA

(WittH PLATES 106 TO 126)

BY
CHARLES D. WALCOTT

aeenee* 2 INcp =

(PUBLICATION 2753)

The Lord Baftimore Press

BALTIMORE, MD., U. S, A-

CAMBRIAN GEOLOGY AND PALEONTOLOGY

No. 9—CAMBRIAN AND OZARKIAN BRACHIOPODA,
OZARKIAN CEPHALOPODA AND NOTOSTRACA

By CHARLES D. WALCOTT
(With PrateEs 106-126)

CONTENTS Me

lingmalmeiemn 53. certhe Rew Series SS bbe Ono Re ne cee coon cmiromtrrian fans 479
Sareea TRF re ne et et teenies sy nec alne ops ata b'eisle setae e es 481
PRC EIB Ie SHCCIOG, cians a hierrek oer oo ccyslaje «Sf Sina cles ae eo 8 eel welel em oaierals 481
Genrisw Vic ronaitramileenpr sr won atin ce cians otis aceecre oe o.e ficvels <1 o\te cle ere sy sie 481
Micromitra zenobia Walcott, Middle Cambrian.................. 481
Micromitra (Iphidella) pannula (White), Middle Cambrian...... 482
GenGe ObollistebiGhnvalders nissccas coos ces oe se wisisisle ects Oe ewes ces 482
Walesa: nispacOaaintat CNLONS). 2. seis aces asec sc sseess 482
Obolus leda Walcott, Ozarkian (Notch Peak)..............-... 483
Opolus myron, 2. sp Upper Cambrian. 2)... 6. ones ees eee ee a’ 484
Opelus perone, 1).s5p., Upper Cambrian: 12525 22. coe gk ee eee eee 484
Obolus tetonensis Walcott, Ozarkian (Chushina)................ 484
Obolus cf. tetonensis Walcott, Ozarkian (Mons)................ 485
@iaius teuta,n.- sp, Ozarkian (Mons) 2.25 osc 12 e eee oe aes 486
bolus: whympeti, n. sp.ecower Cambrian. 0.0... 6. 65 ee nts 487
Obolus (Westonia) ollius, n. sp., Upper Cambrian............... 487
Obolus (Westonia) tertia, n. sp. Ordovician (Sarbach)......... 487
Obolus (Fordinia) nestor, n. sp., Upper Cambrian............... 488
Geng JL. Ja EN oreddn ecco on boo padodadce onde Sbooao oS Sono oe 488
igmeulepis nabis, mn sp, Ozarkian’ (Mons)... 25.0.2 as eee ss 489
enicmleine(tellaw Saltense sree tic tcleterscirtestshisicie tecei=. elev everett 2Tse "ols 490
Lingulella cf. desiderata Walcott, Ozarkian (C. and M.)*......... 490
finewlella tbicus, wsp4 Ozarkian-(Caand M2)\2..4 2s... 0.232 ess 491
Binemellasmiltondans sp" Ozarkdanhe- ts cease sie cae ele see Ss 492
Mimenlellaymectioss me sp, Ordoviciany (Sanbach)ij..-..c6. -2 +2. -<- 492
aaeiltelia nepos, n. sp. Ozarkian (Mons). 2.2 ...25002.05...2.4 5. 493
Gmowella nerva, nm. spi, Ozarkian (Mons).20s...4. 6.2222 0042s. 493
inemellarnintus, mm sp.) Ozankian aC@hushinaiessse cae cee sce 4s... 494
iinetilellarremius, iy sp Ozarkiane (Gs angels) eeiseciaesn cae as oe 494
Pimanellarsiiquasn: sp. Upper Canibriatia ecm. sees es acs «- 495
Lingulella cf. similis Walcott, Ozarkian (Mons)..... aoe 495
Lingulella waptaensis, n. sp., Middle Cambrian................... 496

*C. and M.=Chushina and Mons formations.

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 9
477

478

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

PAGE

Genus Acrotreta Kutotga . ss .csne sf eseje ned sm se enleleeanaialo 496
Acrotreta atticus, n. sp., Ozarkian (Chushina).............-.--- 496
Acrotreta discoidea, n. sp., Ozarkian (Chushina)..............-- 497
Acrotreta cf. microscopica Shumard, Ozarkian (Mons)......... 497
Genus Acrothyra Matthew ic. nte< 0206 ce © dee 0 on aire cients nine eee 498
Acrothyra gregaria, n. sp.. Middle Cambrian...........-.---..-+ 4908
Gentts Nisusia Wralott.< .</i,cicece ace + aleve ote spores cusle te ebeusie depeneise teneyaeeneneteae 4908
Nisusia spinigera, n. sp. Upper Cambrian... ....2...... 7. seen 498
Nisusia burgessensis, n. sp., Middle Cambrian................... 499
Nisusia (Jamesella) oriens, n. sp., Lower Cambrian.............- 500
Genus Wamanellay Walcott ccc sctjetcc e iceiem cre 1s eset = rake erate eter 500
Wimanella borealis, n. sp., Middle Gambriany..---. ose eee 501
Wimanella occidens, n. sp., Upper Cambrian. ... .. <0: aetna SOI
Genus Billinesella. Halland Clarke.ot. si sic. ccs e's ones ctoe 501
Billingsella archias, n. sp., Ozarkian (C. and! M.).-..-<.- eee 501
Billingsella ‘olen, ‘n. sp., Ozarktan (Mons))<..... <i. 0s) seen 502

Billingsella origen, n. sp., Ozarkian (Mons)
Genus Protorthis Hall and Clarke

Protorthis iones, n. sp., Ordovician (Sarbach), Ozarkian (Mons). 503

Protorthis porcias, n. sp., Ordovician (Sarbach), Ozarkian (Mons) 504
Genus Eoorthis Walcott

so ayes Nidrace abe: oohe OBESE e Oran vol otu se 505
Eoorthis bellicostata, n. sp., Middle Cambrian................... 505
Hoorthis) desmopleura @Miecek):, Ozarkianes. 5-6 see see eee 506
Hoonthisstascicera, nu. sp Wpperm Cambictans se eee eine een 507
BHoosthisuophon) nasp:,Ozarkian: (Moms) pen cease aes 508
Hoorthis limeocosta, m sp. Ozankian! (Mlanitow)ic.22 rene 508
Eoorthis-ochus, acesp., ‘Ozarkian ((Momns)).....2-.0, ets eee 509

Eoorthis putillus, n. sp., Ozarkian (C. and M.)
Eoorthis putillus laeviuscula, n. var., Ozarkian (Mons).......... 511
Eoorthis vicina, n. sp., Ozarkian (Mons)

Eoorthis wichitaensis Walcott, Upper Cambrian, Ozarkian (Mons) 513
Genus Finkelnburgia Walcott

ajidns a: cio! destin eile a vale Atavevaughel crake kee kao 514
Finkelnburgia noblei, n. sp., Upper’ Cambrian........s20. eee 514
Fainily Syntrophidae) .2.0.4¢ <c.1;.c.sernncet ce soe ae ne Ce ee 515
Genus Syntrophia Halland Clarke: :....< cc. se eaeeel eee 515
Syntrophia cf. calcifera Billings, Ozarkian (Mons).......... 516
Syntrophia isis, n: sp..,Ozarkian (Mons) ..ss+. 455-2 eee 517
Syntrophia nisis, n:. sp. Ozarkaan. (Mons)\-c..- eee 517
Syntrophia nonus, n.'sp., Ozarkian (Moms)....:..:....400e8 518
Syntrophiia perilla, n:.sp., Ozarkian (Mons)i-.... 425.0 eee 519

Genus: Efuenella’ Walcott ssc.cscia.kexeioawkie oh ne see oe eee 520
Huenellashera, ny sp; Upper. Gambrian..c...¢. aceon nee 520
Huenellaicetas,n. sp, ‘Ozarkian (Mons)... uss. ase 520
Huenella juba, n_sp:, Ozarkiany (Mons) =. ose. eee 521

Huenella simoni nsp., Upper Cambrian... o2.0 eee eee 521
Huenella texana Walcott, Upper Cambrian
Huenella ? weedi, n. sp., Upper Cambrian

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 479

PAGE

Brachiopods from Island of Novaya Zemlya, Russia..................00. 523

Shans. CWestonia) spy wndt.... 2:12. .0 2s -Se< wane - ‘SA US ke ae aa 523

inealellarctecdestdenatamVValcotts. scr ec cise eek Chee oe bone 524

PP irecelell a MARGHICARE VY CICIEE Do ai20 os sia e/aluis Re bine ease oie wieiale bee Sea cokes o's 524

PNETOCLELOMSDEMIING tetra nes care Areca Actne Sateen ee ween ee 52

Enuneseila, boljedalsis» Walcott. cc. c-. 002 coew eect botiacsasdag estes 525

iinoseiia ar cipieg Walcott. . sx ac onl ooteks Mele aera aca aw ud ees 525

IES LUE ee STONE) (500) 4 oe a a te cS A ae 526

bene rei Micatae NV AICOLE 1s csiee's se bo a be ae keels ae ee ca kok 526

(CORBET SOG SUIS SAU osc Stn ne DA yo RE, re ee cn Be 527

Senesuedlesmenocetas MOCESEES «5-54 1a) 0, + 4vicc ce ddan else ahiee cea be 527

Ellesmeroceras robsonensis, n. sp., Ozarkian (C. and M.)......... 527

Endoceras (?) monsensis, n. sp., Ozarkian (C. and M.).......... 5290

Sette ON CEO SUL ACI SCOOP tates oe tale weislaeieu v's a\ctle tebe a clda OC oon seat 530

Baniyedbechnophordaer Miller c.c ts soem. clas soca nts ees Ch 530

AGEN SHO) AOM ea TI SHeC CMMI T Sioxanctsk shots 0) chey.cua cole apex suc Meets ek ocr 531

Ozomia lucan, n. sp., Ozarkian (Mons and St. Charles)...... 531
ILLUSTRATIONS

FACING

PAGE

BlafeseiOO= 12 5raw ShAChiOpodare as wis.c.o cc tdi o> 6. 6s Gratec elegy omterseitenaee es 534-553

Piateeiete Cepnalapoda, NOLOSEBACA <is265 oy cieicies sacle a « ajyaciecss s% ees as cien 554
INTRODUCTION

The field reconnaissance of the pre-Devonian formations of Alberta
and British Columbia, Canada, that I have been conducting the past
six seasons has resulted in the accumulation of collections that have
received preliminary study and are now being prepared for illustra-
tion and description.

The first paper resulting from this field-work was issued in March,
1923, on the “ Nomenclature of Some post-Cambrian and pre-Cam-
brian Formations.”* In this, preliminary lists of fossils are given
and among them three brachiopods that are described in this paper,
Lingulella ibicus Walcott, Eoorthis iones Walcott, Syntrophia isis
Walcott. E. tones is now referred to Protorthis.

In addition to the above there are 50 new species and one variety
listed in the table of contents. These include not only those from the
Cordilleran area of Canada, but a few from various localities in the
United States that have been found in older collections from various
sources now in the U. S. National Museum.

* Smithsonian Misc. Coll., Vol. 67, No. 8.

480 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

The species are distributed as follows :

Ordovician, <:g¢.9.-2- se. see ONE tery Seek 6
Ozatkidia sedis Shc ba ai oe nee Oe ee eee 26
Cambrian 024.6 sf enht eee oe oe See Es eee 20
52

Gommion to Ozarkianand) Ordovician.) ole ese eee 2
Total mew SPECIES i244 <5 yee es oe Dee 50

One new variety.

Brachiopods are relatively rare in genera and species in the forma-
tions in which I have been working in Alberta and British Columbia.
This in a measure is owing to their destruction by wave and current
action, and also to the fact that conditions accompanying the great
calcareous deposits do not appear to have afforded them a favorable
habitat. An occasional quiet bay or inlet provided food and shelter
from the strong tides and currents, and in these, colonies of a few
species flourished in great numbers.

The species described by me since the preparation of Monograph
51, published in 1912 are

Obolus mollisonensis Walcott?
Lingulella moosensis Walcott’?
Lingulella ? allani Walcott”
Mickwitzia muralensis Walcott °
Lingulella chapa Walcott °
Lingulella hitka ‘Walcott *
Obolella nuda Walcott *
Micromitra (Paterina) charon Walcott *
Obolus damo Walcott *
Acrothele clitus Walcott *
Wimanella catulus Walcott *

The present paper also includes the only two cephalopods, and one
Notostracan thus far discovered in the Mons formation. The study
of the gasteropoda of the Sarceen ° formations is well advanced, also
the description and illustration of new genera of trilobites. It is
planned to include these papers in Volume 75 of Smithsonian Mis-
cellaneous Collections.

Through the courtesy of Dr. Olaf Holtedahl, I have had the oppor-
tunity of studying a small collection of brachiopods from Novaya

*Mong. U. S. Geol. Surv., No. 51, 1912.

? Smithsonian Misc. Coll., Vol. 57, No. 7, 1912, pp. 231, 232.
* Idem, No. 11, 1913, pp. 310-312.

*Smithsonian Misc. Coll., Vol. 67, No. 3, pp. 69-70.

* Smithsonian Misc. Coll., Vol. 67, No. 8, 1923, p. 471.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 481

Zemlya, Russia, which he discovered there The brachiopods are
described and illustrated in this paper and they will also be published
later in Norway with the associated trilobites. The fauna is essen-
tially of a lower Ozarkian Mons facies and belongs, as Dr. Holtedahl
states, with the Pacific Province and not the Atlantic. The genera
and species of brachiopods include Lingulella cf. desiderata Walcott,
L. arctica n. sp., Acrotreta sp. undt., Obolus (Westonia) sp. undt.,
Billingsella holtedahli n. sp., B. ? oppius n. sp., Eoorthis sabus n. sp.,
Auenella triplicata n. sp.

The photographs of brachiopods illustrated in this paper were made
by Dr. Charles E. Resser, of the U. S. National Museum, and the
retouching of photographs was done by Miss Francis Wieser.

BRACHIOPODA
DESCRIPTION OF SPECIES
Genus MICROMITRA Meek

See Mong. U. S. Geol. Surv., No. 51, 1912, p. 332, for synonymy, description
and illustration.

MICROMITRA ZENOBIA Walcott
Plate 106, figs. 1-7

Micromitra zenobia Walcott, 1912, Mong. U. S. Geol. Surv., No. 51, p. 342,

text fig. 23. Describes and illustrates species with one text figure.

The type of this species occurs in the Burgess shale of the Stephen
formation, and the specimens illustrated in this paper occur in a
calcareous shale about 1,000 feet (304.8 m.) distant from the type
locality and a little above the horizon at the type locality. All the
shells are flattened and more or less distorted; none of them exhibit
the interior surface and only traces of the pseudo cardinal area are
preserved; they afford, however, fine illustrations of distortion with
considerable fracturing of the test of the shell, and are worth illus-
trating on that account.

The associated fossils are:

Pirania muricata Walcott

Obolus sp. undt.

Hyolithellus flagellum Matthew
Hyolithes sp. undt.

Scenella varians Walcott
Ptychoparia ? cordillere (Rominger)
Neolenus serratus (Rominger )

* Amer. Jour. Sci., 5th Ser., Vol. 3, 1922, pp. 343-348.

482 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Formation and locality—Middle Cambrian: (61j) Stephen for-
mation. Buff weathering band of calcareo-argillaceous shale. West
slope of Mt. Field, near Burgess Pass Ridge about 3,200 feet
(975.3 m.) above Field on the Canadian Pacific Railway, British
Columbia, Canada.

MICROMITRA (IPHIDELLA) PANNULA (White)
Plate 106, figs. 16, 17
For synonymy see Mong. U. S. Geol. Surv. No. 51, 1912, p. 361.

Two specimens of this species are illustrated on account of the
fine preservation of the delicate spines or sete attached to the surface
of the shell. Many hundreds of these shells from calcareous shales
were without a trace of the spines, but in the fine silicious Burgess
shale several have them attached.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation. On the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of
Burgess Pass, above Field on the Canadian Pacific Railway, British
Columbia, Canada.

Genus OBOLUS Eichwald
See Mong. U. S. Geol. Surv., No. 51, 1912, for synonymy and description.

OBOLUS ION, new species
Plate 106, figs. 8-10

This is a medium size species of Obolus comparable with O. teton-
ensis Walcott.’ It has similarly shaped valves except that some of the
ventral valves of O. ion are more acuminate, in this respect resembling
the ventral valve of Lingulella acutangula Roemer, but the dorsal
valves have more the outline of those of Lingule pis.

Dimensions —Ventral valve 7 mm. in length, maximum width
6 mm. Dorsal valve 6 mm. in length, 5.5 mm. maximum width.

Formation and locality—Ozarkian: (16q) Mons _ formation.
Thin-bedded gray limestone. Brisco range, about 2 miles (3.2 km.) up
Sinclair Canyon from Radium Hot Springs on north side of canyon
near north end of 3d bridge on Banff-Windermere motor road.
About 15 miles (24.1 km.) from Lake Windermere in Columbia
River Valley.

* Mong. U. S. Geol. Surv. No. 51, 1912, p. 417, pl. 9, figs. 5, 5a-c.
* Idem, pl. 17, fig. 1.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 483

(16y) Mons formation; compact gray limestone crowded with
broken fossils; Brisco Range, north side of Sinclair Canyon about
500 feet (152.4 m.) above stream on edge of cliff and about 400 feet
(121.9 m.) up the canyon from the first bridge west on Banff-Winder-
mere motor road.

(17n) Mons formation; thin gray nodular limestone interbedded
in argillaceous shale. North side of Stoddart Creek Canyon near its
mouth, 6 miles (9.6 km.) south of Sinclair Canyon, Stanford Range,
on east side of Columbia River Valley, all in British Columbia,
Canada.

OBOLUS LEDA Walcott
Plate 106, figs. 12-15
Obolus. tetonensis leda Walcott, 1912, Mong. U. S. Geol. Surv., No. 51, p.
417. (Variety described but not illustrated.)

This is the representative in the basal portion of the Ozarkian
Notch Peak formation of Obolus tetonensis Walcott which occurs in
the Upper Cambrian of the Teton Mountains of Wyoming. It differs
from O. tetonensis in its more elongate dorsal valve, thinner shell and
finer concentric surface striz.

Dimensions —A large ventral valve 3.5 mm. in length has a maxi-
mum width of 2.5 mm. A dorsal valve 5 mm. long has a maximum
width of 3.5 mm.

Formation and locality—Ozarkian: (30 m.) Notch Peak forma-
tion. Compact dove colored limestone 140 feet (42.6 m.) from base
of te of section. North slope of Notch Peak about 5 miles (8 km.)
south of Marjum Pass, House Range, Millard County, Utah.

A shell that is closely related’to O. leda occurs with the Hungaia
faunule of the Stanford Range. It has the same thin, shiny shell and
form, but is a little larger.

Ozarkian: (17p) Mons formation. Thin layer gray limestone
interbedded in argillaceous shale, north side of Sinclair Canyon about
450 feet (137.1 m.) above creek, and a little west of Radium Hot
Springs, Brisco Range.

(17v) Mons formation. Thin layer of soft gray limestone inter-
bedded in shale 1g of section and 221 feet (67.3 m.) above base of
section. Southwest angle of Sabine Mountain, 1 mile (1.6 km.)
north of Kootenay River Bridge and about 2 miles (3.2 km.) nortli-
east of Canal Flats Station on the Canadian Pacific Railway.

(211) Mons formation. Thin-bedded gray limestone interbedded
in shale. Kicking Horse Canyon above second bridge on Canadian
Pacific Railway, about 1.5 mile (2.4 km.) east of Golden. All in
British Columbia, Canada.

484. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

OBOLUS MYRON, new species
Plate 107, figs. 1-3

In outline of the valves, this species recalls Obolus mcconnelli
Walcott from the Middle Cambrian, especially the variety decipiens,’
but the nearest species is Obolus tetonensis Walcott and its variety
ninus.” Both species are from the Upper Cambrian. O. myron differs
from O. tetonensis in the broader outline of the valves and more
obtuse apex of the ventral valve.

Dimensions.—A ventral valve 7.5 mm. long has a maximum width
of 5.5 mm. A flattened and distorted dorsal valve is 5.5 mm. long and
7 mm. in width.

Formation and locality ——Upper Cambrian: (63x) Ottertail for-
mation. Thin-bedded limestones about 500 feet (152.4 m.) above
argillaceous shales of Chancellor formation ; Wolverine Pass between
Mounts Drysdale and Grey (11 miles (17.6 km.) southwest of Ver-
milion Pass, Alberta), in British Columbia, Canada.

OBOLUS PERONE, new species
Plate 106, fig. 11

This species is represented by a few fragments and one dorsal
valve that proves it to have been a rather large and thick shell marked
by concentric striz and lines of growth. This dorsal valve is a little
distorted but it appears to have been wider than long, the length being
II mm. and maximum width 14 mm.

The one imperfect specimen indicates a species related to Obolus
maera (Hall and Whitfield), (Mong. U.S. Geol. Surv., No. 51, 1912,
pl. 10, figs. 2, 2a-e) and it may be compared with compressed forms
of Obolus apollinis Eichwald (idem, pl. 14, figs. 6, 6a).

Formation and locality——Upper Cambrian: Ottertail limestone on
Moose river southeast of Field, British Columbia, Canada.

Type in collection of Geological Survey of Canada at Ottawa.

OBOLUS TETONENSIS Walcott
Plate 107, figs. 4, 5
Obolus tetonensis Walcott, 1901, Proc. U. S. Nat. Museum, Vol. 23, p. 684.
(Described as a new species. )
Obolus tetonensis Walcott, 1905, Idem, Vol. 28, p. 327. (Same as above.)
Obolus tetonensis Walcott, 1912, Mong. U. S. Geol. Surv., No. 51, p. 417,
pl. 9, figs. 5, 5a-d. (Species discussed, illustrated and localities given.)
This form of Obolus is widely distributed in the Cordillera of
western North America. It occurs in the Bisbee District of Arizona,

* Mong. U. S. Geol. Surv., No. 51, 1912, pl. 23, figs. 3a, 4.
* Loc. cit, pl. 0,"higs. '5,-Sa-¢ "pl. 11, fhes. tag.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 485

the Teton Mountains of Wyoming, and at several localities in Mon-
tana, and as far as I can determine from the ventral valves it is present
in the Mount Robson section of British Columbia. The figures of the
two valves illustrated on plate 107, figures 4, 5, may be compared with
those of two of the ventral valves from the type locality. (See pl.
Q, figs. 1, 1a, Mong. 51, U. S. Geol. Surv.)

The types of O. tetonensis occur in association with Lingulepis
acuminata meeki Walcott, Billingsella coloradoensis (Shumard) and
Acrotreta microscopica tetonensis Walcott. This fauna of locality 4e
is referred to the Middle Cambrian by Walcott (Mong. 51, p. 417),
but this is evidently a mistake as my field label has Upper Cambrian
on it, and the fauna as I understood it in 1898 was of Upper Cambrian
age. Now that this fauna has been removed from the Upper Cam-
brian and placed in the Ozarkian, O. tetonensis and its associates at
locality 4e will be referred to the lower zone of the Ozarkian. All of
the localities of O. tetonensis are either in the Upper Cambrian or
basal Ozarkian. This is evidently the case with locality 4h (Mong. 51,
p. 166) which also has Lingulepis acuminata Conrad, a species that
occurs most abundantly in the Lower Ozarkian Hoyt limestone fauna
of New York.

The stratigraphic references to Upper and Middle Cambrian in
Monograph 51 are subject to revision as they were made at a time
when the boundaries of the Upper Cambrian in the Cordilleran area
were not well established. O. tetonensis appears to have lived in the
Upper Cambrian seas and continued on into the Lower Ozarkian,
and an almost identical form occurs in the lower Canadian fauna of
Fossil Mountain (locality 67n) (pl. 107, figs. 7, 7a, 8), except that
the latter has the exterior surface of a Westonia.

Dimensions —A ventral valve 9 mm. in length has a maximum
width of 7 mm. and an associated dorsal valve 7 mm. in length has
a maximum width of 7 mm.

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. In Billings Butte (Extinguisher) at end of west spur
of Mount Lynx, above Hunga Glacier and east of Robson Peak,
Robson Park, northwest of Yellowhead Pass, in eastern British
Columbia, Canada.

OBOLUS cf. TETONENSIS Walcott

Obolus tetonensis Walcott, Mong. U. S. Geol. Surv., No. 51, 1912, p. 417, pl.
9, figs. 5, 5a-d. (Described and illustrated.)

A few fragmentary specimens of a species closely related to O.
tetonensis were found in a hard gray limestone of the lower Mons

486 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

formation in the Glacier Lake section. Comparison may also be made
with Obolus matinalis (Hall) from the Upper Cambrian, Franconia
sandstone of Wisconsin. Better specimens are needed for study and

illustration before a satisfactory specific identification can be made:

Formation and locality—Ozarkian: (64n) Mons formation
(Lower) near base of Ic of field section. Cliff on southeast side of
Mons Glacier above head of Glacier Lake Canyon Valley about 50
miles (80.5 km.) northwest of Lake Louise Station on the Canadian
Pacific Railway, Alberta, Canada. Similar specimens occur at the
following localities:

(16u) Mons formation. Beds of dove gray limestones 30 inches
(76.2 cm.) thick, interbedded in gray argillaceous shale. South end
of Brisco Range, north side of Sinclair Canyon about 600 feet
(182.8 m.) above the creek and 700 feet (213.3 m.) west of Radium
Hot Springs.

(16y) Mons formation. Compact gray limestone crowded with
broken fossils. Brisco Range, north side of Sinclair Canyon about
500 feet (152.4 m.) above stream on edge of cliff and about 400 feet
(121.9 m.) up the canyon from the first bridge west on Banff- Win-
dermere motor road.

(21e) Mons formation. Gray thin-bedded limestones. South end
of Brisco Range on northeast side of Sinclair Canyon about 800 feet
(243.8 m.) up the canyon from the first bridge west of entrance to
canyon on the Banff-Windermere motor road.

(17y) Mons formation. Hard gray limestone. West slope of
Stanford Range, east side of Columbia River Valley, 5 miles (8 km.)
south of Sinclair Canyon and .5 mile (.8 km.) north of Stoddart
Creek. All in British Columbia, Canada.

OBOLUS TEUTA, new species
Plate 107, fig. 6

This is one of the Obolus tetonensis-like forms that occurs in a
slightly different zone of the Mons formation than O. ion. It is much
like the latter but differs in its less acuminate ventral valve and less
elongate dorsal valve. The latter is somewhat like the dorsal valve
of O. tetonensis. |

Dimensions.—A ventral valve 9.5 mm. in length has a maximum
width of 7 mm. A dorsal valve to mm. long has a width of 8 mm.

Formation and locality—Ozarkian: (16r) Mons formation, Brisco
Range, north side of Sinclair Canyon about 1,200 feet (365.7 m.)
above bridge No. 5, on Banff-Windermere motor road, British
Columbia, Canada.

~~ oa

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 487

(17y) Mons formation; west slope Stanford Range, east side of
Columbia River Valley, 5 miles (8 km.) south of Sinclair Canyon
and 0.5 mile (.8 km.) north of Stoddart Creek, British Columbia,
Canada.

OBOLUS WHYMPERI, new species
Plate 121, figs. 4-7

This is one of the Obolus mcconnelli forms of Obolus that occurs
at a lower stratigraphic horizon in the silicious shales beneath the
upper calcareous beds of the Mt. Whyte formation. It differs prin-
cipally from O. mcconnellt (Walcott) in the more elongate outline
of the valves and average larger size. The shells are fairly abundant
on the surface of a hard, fine, arenaceous, gray shale that occurs on
the lower slopes of Mt. Whymper.

The species is named in honor of Edward Whymper, explorer and
mountain climber in the Canadian Rockies.

Formation and locality—Lower Cambrian: (68e) Mt. Whyte for-
mation, east lower slope of Mt. Whymper, above Vermilion Pass,
British Columbia, Canada.

OBOLUS (WESTONIA) OLLIUS, new species
Plate 121, figs. 8-10

Lingulella stoneana Weller, 1903, Geol. Surv. New Jersey, Rept. Pal., Vol. 3,
p. 112, pl. 1, fig. 6. (Described and discussed.)

Lingulella stoneana Whitfield Weller, 1903, Geol. Surv. New Jersey, Rept.
Pal., Vol. 3, p. 112, pl. 1, fig. 6. (Described and discussed.)

Obolus (Westonia) stoneanus Walcott, 1912, Mong. U. S. Geol. Surv. No. 51,
p. 465, pl. 40, figs. 2, 2a. (Illustrates specimen from New Jersey now
referred to O. (W.) ollius.)

This species differs from O. (W.) stoneanus (Whitfield) of the
Upper Cambrian of Wisconsin in outline and in the direction of the
raised transverse outlines which bend back on the cardinal and lateral
slopes more towards the beak than in O. (W.) ollius.

Formation and locality—-Upper Cambrian (11c) “ Hardystone
Quartzite,” Newton, New Jersey.

OBOLUS (WESTONIA) TERTIA, new species
Plate 107, figs. 7, 7a, 8
The striking difference between this species and Obolus dolatus
Sardson * of the Oneota dolomite is in the character of the outer sur-
face. On O. (W.) tertia the concentric raised lines of growth are
strong, irregularly spaced, and the entire surface is slightly roughened

*Mong. U. S. Geol. Surv., No. 51, p. 390, text figs. 35a-c.

488 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

by very minute inosculating raised lines that give almost the same
effect as similar lines on the surface of Obolus (Westonia) ella Hall
and Whitfield.’

It is closely related to the latter widely distributed species by surface
characters and form of ventral valve, but the outline of the dorsal
valve is less transverse.

Dimensions.—A convex ventral valve 8 mm. long has a maximum
width of 6.75 mm. A flattened ventral valve 6.5 mm. long is 7 mm.
in maximum width.

Formation and locality Ordovician: (67n) Sarbach formation,
in a hard, dirty gray, thick-bedded limestone weathering to a light
buff color. Northeast slope of Fossil Mountain, 8.7 miles (13.9 km.)
northeast of Lake Louise Station on the Canadian Pacific Railway,
Alberta, Canada. Also (210) Buff brown and gray shaly limestone
75 feet (22.8 m.) below 2In. On low ridges southeast of lower
end of Baker Lake and Fossil Mountain.

OBOLUS (FORDINIA) NESTOR, new species
Plate 108, figs. I, 2

This species is founded on a dorsal valve showing the cast of a
portion of the visceral area and the exterior of an associated ventral
valve. The dorsal valve resembles that of Elkania desiderata (Bil-
lings) (Mong. 51, pl. 51, fig. 1d), and the ventral valve that of Obolus
(Fordinia) gilberti Walcott (loc. cit., pl. 51, fig. 5). The generic
reference is doubtful as the dorsal valve does not show sufficient of
the visceral area to clearly indicate whether it belongs to Obolus
(Fordima), Elkania, or Dicellomus.

Dimensions—The dorsal valve is 6.5 mm. in length with a maxi-
mum of 7mm. The associated ventral valve is smaller with a length
of 3.5 mm. and a maximum width of 3 mm.

Formation and locality—Upper Cambrian: (64w) Lyell formation.
Drift blocks of limestone. Sawback Range, Ranger Brook Canyon,
10 miles (16 km.) in air line west-northwest of Banff, and 2 miles
(3.2 km) north-northeast of Massive Switch on Canadian Pacific
Railway, Alberta, Canada.

Genus LINGULEPIS Hall
See Mong. U. S. Geol. Surv., No. 51, 1912, p. 544, for synonymy and de-

scription.
For convenience of reference and listing of species I have during
the past few years been using Lingulepis as a genus rather than as a

“LOC. cht, pl vA7, fies s10:

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 489

subgenus of Lingulella. The attenuate form of the posterior por-
tion of the ventral valve is, however, so persistent and so well marked
that it may be as well to return to the usage of the author of the genus
and give Lingulepis full generic value. It is a very excellent horizon
marker in the Lower Ozarkian and Upper Cambrian formations of
the Cordilleran and Appalachian areas and of the Middle Cambrian
in New Brunswick. The species L. acuminata (Conrad) is widely
distributed in the Appalachian area and the Mississippi Valley, and
similar forms occur at Mount Robson, British Columbia, and far to
the south in the Cordilleran ranges of Utah and Nevada.

The species I have described as L. nabis is the only new one that has
come to my attention since IgIo.

LINGULEPIS NABIS, new species
Plate 100, figs. 4-7

This species differs from Lingulepis acuminata (Conrad) * in its
uniformly smaller size, nearly straight lateral margins of the ventral
valve and more elongate dorsal valve; it also appears to have had a
thinner more flexible shell. The ventral valve resembles that of some
forms of Lingulepis exigua (Matthew) (loc. cit., pl. 43, figs. 1-1b)
from the Middle Cambrian, but the dorsal valve is quite unlike the
dorsal valve of L. exigua. The latter species is also much larger. It
may also be compared with L. spatula Walcott (loc. cit., pl. 19, figs. 5,
5a, 50) from the Bright Angel shale formation.

A species closely resembling L. nabis occurs with a faunule of the
Mons fauna in Sinclair Canyon. Unfortunately the specimens are all
imperfect, which prevents close comparison and identification.

Dimensions—A small ventral valve 4.25 mm. in length has a
maximum width of 2.75 mm. A large dorsal valve 7.25 mm. in length
has a maximum width of 4 mm.

Formation and locality—Ozarkian: (16q) Mons formation in a
thin-bedded gray limestone. Brisco Range, about 2 miles (3.2 km.)
up Sinclair Canyon from Radium Hot Springs on north side of can-
yon near north end of third bridge on Banff-Windermere motor road.
Also locality 16t which is about a mile further down Sinclair Canyon.

(16v) Mons formation. Soft gray thin-bedded limestone. Brisco
Range, north side of Sinclair Canyon about 75 feet (22.8 m.) above
the creek just below the fourth bridge on the Banff-Windermere
motor road, which is 4 miles (6.4 km.) above the first bridge.

* See Mong. U. S. Geol. Surv., No. 51, pt. 2, 1912, pls. 40-42.

490 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

(17n) Mons formation. Thin layer gray nodular limestone inter-
bedded in argillaceous shale. North side of Stoddart Creek Canyon,
near its mouth, 6 miles (9.6 km.) south of Sinclair Canyon, Stanford
Range, on east side of Columbia River Valley. All in British
Columbia, Canada.

Genus LINGULELLA Salter
See Mong. U. S. Geol. Surv., No. 51, 1912, for synonymy and description.

LINGULELLA cf. DESIDERATA Walcott
Plate 108, figs. 3, 4

Lingulella desiderata Walcott, 1898, Proc. U. S. Nat. Mus., Vol. 21, pp. 390-
400. (Described and discussed as a new species.)

Lingulella desiderata Walcott, 1921, Mong. U. S. Geol. Surv., No. 51, p. 492,

pl. 20, figs. 4, 4a-c, 5, 5a-].

This widely distributed species that ranges from the Upper Cam-
brian into the Lower Ozarkian in the United States, is represented
in the Mons fauna by a small shell that cannot readily be separated
from the typical forms of the species. The ventral valve is similar
but the one associated dorsal valve is more like that of L. rotundata
(loc. cit., pl. 20, fig. 2d).

The shell is thin and marked by fine concentric striz.

Dimensions —Ventral valve 4.75 mm. in length with a maximum
width of 2.75 mm.

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. In Billings Butte (Extinguisher) at end of west spur of
Mount Lynx, above Hunga Glacier and east of Robson Peak, Robson
Park, northwest of Yellowhead Pass, in eastern British Columbia.

Ozarkian: (16t’) Mons formation. Thin layers of limestone inter-
bedded in gray argillaceous shale. Brisco Range, north side of Sin-
clair Canyon about 500 feet (152.4 m.) above creek and a little west
of Radium Hot Springs.

(21d) Mons formation. Argillaceous shale and thin layers of
dense gray limestone. Northern end of Stanford Range on southeast
side of Sinclair Canyon just below Radium Hot Springs Pool. All in
British Columbia, Canada.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 491

LINGULELLA IBICUS, new species
Plate 108, figs. 5-8, plate 109, figs. 8, 9

The general form of this, species is not unlike that of L. bella Wal-
cott and L. randomensis Walcott * from the Upper Cambrian of New-
foundland. The valves of L. ibicus are more elongate than those of
L. bella, and broader posteriorly than those of L. randomensis. Shell
thin and marked by fine concentric strize and lines of growth.

Dimensions—A ventral valve 8.5 mm. in length has a maximum
width of 4.75 mm., and a small dorsal valve 5.5 mm. long has a
maximum width of 4.25 mm.

A dorsal valve of a Lingulella occurs in the Lyell formation of the
Upper Cambrian (locality 64c) that is very similar to that of L.
tbicus in outline and convexity. It may also be compared with the
dorsal valve of L. bella Walcott (Mong. 51, pl. 19, figs. 2b, 2c).

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. In Billings Butte (Extinguisher) at end of west spur of
Mount Lynx, above Hunga Glacier and east of Robson Peak, Robson
Park, northwest of Yellowhead Pass, in eastern British Columbia.

(16q) Mons formation. Thin-bedded gray limestone. Brisco
Range, about 2 miles (3.2 km.) up Sinclair Canyon from Radium
Hot Springs on north side of canyon near north end of third bridge
on Banff-Windermere motor road.

(16y’) Mons formation. Compact gray limestone crowded with
broken fossils. Brisco Range, north side of Sinclair Canyon about
500 feet (152.4 m.) above stream on edge of cliff and about 400 feet
(121.9 m.) up the canyon from the first bridge west on the Banff-
Windermere motor road.

(17n) Mons formation. Thin layer gray nodular limestone inter-
bedded in argillaceous shale. North side of Stoddart Creek Canyon
near its mouth, 6 miles (9.6 km.) south of Sinclair Canyon, Stanford
Range, on east side of Columbia River Valley.

Loc, pl 10; ties.<2920-f and pl; 2g. 5.
2

492 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

(17y) Mons formation; west slope Stanford Range, east side of
Columbia River Valley, 5 miles (8 km.) south of Sinclair Canyon
and .5 mile (.8 km.) north of Stoddart Creek, British Columbia,
Canada.

(21f) Mons formation. Hard gray limestone interbedded in shale.
North end of Stanford Range on southeast side of Sinclair Canyon,
180 to 200 feet (54.8 to 60.9 m.) above first bridge from mouth of
canyon. Allin British Columbia, Canada.

LINGULELLA MILTONI, new species
Plate 122, figs. 1-4

This species is closely related to L. remus (p. 494) in form and
convexity of the valves. It differs in the straighter cardinal slopes
and more transverse front of the ventral valve and the proportionally
narrower and more elongate dorsal valve. There is considerable varia-
tion in the widening of the ventral valve as illustrated by figures I and
3. The average length of the ventral valve is about 5 mm. This shell
(L. milton) was compared with L. manticula White in a list of fossils
from Mount Robson’ and the statement made that the fauna was very
close to if not within the base of the Ordovician. At that time the
Mons formation had not been determined nor its fauna recognized as
distinct from the Cambrian beneath and the Ordovician above.

L. milton is associated with a rather large species of Acrotreta
closely allied to A. sagittalis transversa (Hartt)* from the Upper
Cambrian of Newfoundland.

The specimens of L. multoni were found in a block of limestone
derived from the beds above the Hungaia zone as exposed in Billings
Butte (Extinguisher) and in the upper beds of lyatunga (rear-
guard) ; these beds probably belong in the Chushina formation.*

Formation and locality——Ozarkian: (61u) Chushina formation.
Gray thin-bedded limestones, northeast slope of Robson Peak in
moraine brought down from high on the mountain by Chupo Glacier
terminating at the lower end of Berg Lake, northwest of Yellowhead
Pass, in eastern British Columbia, Canada.

LINGULELLA NECHOS, new species
Plate 108, figs. 12, 12a
Fragments of a large species of Lingulella are associated with
Obolus (Westonia) tertia (ante, p. 487) that suggest Lingulella davisi

*Smithsonian Misc. Coll., Vol. 57, 1913, p. 336.
* Mong. U. S. Geol. Surv. No. 51, 1912, p. 708, pl. 72, figs. 1, 1a-k.
* Smithsonian Misc. Coll., Vol. 67, No. 8, 1923, p. 458.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 493

(McCoy) from the Lingula Flags of Wales. A dorsal valve has a
length of 15 mm. with a maximum width of 10 mm. It is rather thick
and its outer surface marked by strong concentric lines of growth
following the edges of the laminated layers of the shell. The dorsal
valve is more elongate and rounded subquadrate in outline than that
of Lingulella isse Walcott.’ The thick shell is like that of Obolus
(Lingulobolus) spissus (Billings)?

Formation and locality—Ordovician : (67n) Sarbach formation, in
a hard, dirty gray, thick-bedded limestone weathering to a light butt
color. Northeast slope of Fossil Mountain, 8.7 miles (13.9 km.)
northeast of Lake Louise Station on the Canadian Pacific Railway,
Alberta, Canada.

(210) Buff brown and gray shaly limestone. On low ridges south-
east of lower end of Baker Lake and Fossil Mountain.

LINGULELLA NEPOS, new species
Plate 108, figs. 9-11

The ventral valve of L. nepos is similar to that of L. ninus (pl.
108, figs. 15, 16) except that it is proportionally broader and the
apex is curved over in a less abrupt manner. The associated dorsal
valves are proportionally narrower. Shell thin and marked by fine
concentric striz and lines of growth and fine radiating striz.

Dimensions.—A ventral valve 5.5 mm. long has a maximum width
of 3.5 mm. and a broad associated dorsal valve is 2.25 mm. long with
a maximum width of 2 mm. (fig. 9). An elongate dorsal valve
(fig. 10) has a length of 3.25 mm. and maximum width of 1.75 mm.

Formation and locality —Oczarkian: (16q) Mons formation in thin-
bedded gray limestone. Brisco Range, about 2 miles (3.2 km.) up
Sinclair Canyon from Radium Hot Springs on north side of canyon
near north end of third bridge on Banff-Windermere motor road,
British Columbia, Canada.

LINGULELLA NERVA, new species
Plate 108, figs. 13, I3a, 14
This species of the upper Mons might be a descendant of Lingulella
ibicus or L. remus (see pl. 108, figs. 5-8) of the Ozarkian Chushina
formation, but if so it has changed the outline of the valves, and they
are also much more convex and thicker than the older species. L.
nechos (pl. 108, figs. 12, 12a) is a much larger and more elongate shell.

“ac. Cit.» p2-S10:
“ot. ttt. Pp. 432, pl. 16,, fig. 2:

494. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Dimensions—A convex ventral valve has a length of 7 mm. and a
maximum width of 4.5 mm. A smaller associated dorsal valve is
5-5 mm. in length with a maximum width of 4 mm.

Formation and locality —Ozarkian (16r) Mons formation, Brisco
Range. North side of Sinclair Canyon about 1,200 feet (365.7 m.)
above bridge No. 5, on Banff-Windermere motor road, British Co-
lumbia, Canada.

LINGULELLA NINUS, new species
Plate 108, figs. 15, 16

L. ninus differs from the associated L. ibicus and L. remus in the
more attenuate posterior half of the ventral valve and the broader
dorsal valve. It is not unlike some examples of the shorter forms of
Lingulella perattenuata Whitfield.” Shell very thin with outer surface
marked by fine concentric and radiating striz.

Dimensions ——A small ventral valve 5.5 mm. in length has a maxi-
mum width of 3.5 mm. A large dorsal valve is 7 mm. in length with
a width of 5.5 mm.

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. In Billings Butte (Extinguisher) at end of west spur
of Mount Lynx, above Hunga Glacier and east of Robson Peak, Rob-
son Park, northwest of Yellowhead Pass, in eastern British Columbia,
Canada.

LINGULELLA REMUS, new species
Plate 100, figs. 2, 2a, 3

This is one of the Lingulella acutangula ° type of shells in general
form but it differs in details of outline and its thinner shell. The
nearest species is the associated L. ibicus which differs from it in hav-
ing proportionally more elongate and narrow valves. Shell thin with
outer surface marked by fine concentric striz and lines of growth
and very fine lines radiating from the beak.

Dimensions—Ventral valve 8 mm. long has a maximum width of
5 mm. A dorsal valve 6 mm. in length has a maximum width of
4 mm.

* 66. cil., pl. 2h fies. rc:
* oe che phel7.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 495

Robson Park, northwest of Yellowhead Pass, in eastern British
Columbia, Canada.

Ozarkian (17y) Mons formation. Hard gray limestone. West
slope of Stanford Range, east side of Columbia River Valley, 5 miles
(8 km.) south of Sinclair Canyon and .5 mile (.8 km.) north of
Stoddart Creek, British Columbia, Canada.

LINGULELLA SILIQUA, new species
Plate 108, figs. 17-19; pl. 100, fig. I

This is one of the Lingulella ibicus (see pl. 108, figs. 5-8) group of
shells in which the ventral valve is broad in front with the slightly
rounded sides sloping back to form a somewhat acuminate beak.
Most of the shells are flattened on the surface of a shaly limestone,
but a few have a moderate convexity (fig. 5). The form of the
ventral valve is somewhat like that of L. ninus (pl. 108, fig. 15).
Flattened ventral valves are illustrated by figs. 17, 18, and what may
be a dorsal valve by one of the shorter valves on fig. 19. Shells of
medium thickness with outer surface marked by concentric striz and
lines of growth.

Dimensions.—A. ventral valve 9 mm. in length has a maximum
width of 5 mm. The associated dorsal valve is 8 mm. long with a maxi-
mum width of 5 mm.

Formation and locality —Upper Cambrian: (63x) Ottertail forma-
tion. Thin-bedded limestones about 500 feet (152.4 m.) above argil-
laceous shales of Chancellor formation; Wolverine Pass between
Mounts Drysdale and Grey (11 miles (17.6 km.) southwest of Ver-
milion Pass, Alberta), in British Columbia, Canada.

LINGULELLA cf. SIMILIS Walcott
See Mong., U. S. Geol. Surv. No. 51, 1912, p. 532, pl. 21, figs. 2, 3.

This little shell is abundant in the shales and thin layers of hard
dove-colored interbedded limestone near the base of the Mons forma-
tion in Sinclair Canyon. It closely resembles L. similis, and as a
similar form occurs in the Cordilleran Province in Nevada, it may
have ranged from the Appalachian area of Tennessee across the Mis-
sissippi region and the Black Hills of South Dakota and up through
the Cordilleran trough from the south.

Formation and locality —Oczarkian: (21d) Mons formation; argil-
laceous shale and thin layers of dense gray limestone ; northern end of
Stanford Range on southeast side of Sinclair Canyon just below
Radium Hot Springs Pool, British Columbia, Canada.

490 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

LINGULELLA WAPTAENSIS, new species
Plate 122, figs. 5-8

This is the Pacific Province representative of L. ferruginea Salter
(see Mong. 51, U. S. Geol. Surv., 1912, pl. 29) of the Atlantic Pro-
vince Middle and Upper Cambrian formations of eastern North
America and northwestern Europe. It is a little less elongate and
more rotund in outline but otherwise is very closely related to L.
ferruginea. Nearly all the shells are also a little smaller as they
average about 4 mm. in length and breadth as flattened in the shale.
Often a group of the ventral valves are not over 3 mm. in length,
with a slightly less width. Comparison should also be made with
L. lepis Salter, which is a thicker shell with a somewhat different
outline.

These shells often occur in groups on some of the partings of the
dark silicious shale in the same manner as Obolus mcconnelli.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation. On the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field on the Canadian Pacific Railway,
British Columbia, Canada.

Genus ACROTRETA Kutorga

See Mong. U.S. Geol. Surv., No. 51, 1912, p. 671, for synonymy, description,
and illustration.

ACROTRETA ATTICUS, new species
Plate 1009, figs. 10-12

The ventral valve of this species recalls some of the more elevated
ventral valves of A, sagittalis Salter (Mong. 51, pl. 71, figs. 2, 2a)
but it is more elevated and has a stronger apical callosity ; the scars
of the cardinal muscles are relatively smaller and more elongate.
The exterior form and elevation of the valve is quite similar to the
less elevated valves of A. idahoensis (Mong. 51, pls. 65 and 68) but
the interior of the ventral valve of the latter species differs in the
apical callosity, main vasular sinuses, and cardinal muscle scars. The
associated dorsal valve has a long median ridge extending nearly to
the front margin, which is another character of A. sagittalis that
indicates the close relationship of the two species.

A. atticus is one of the largest species of the genus. A ventral
valve 2.75 mm. in height has a transverse diameter at the margin of
4.5 mm. and a length of 4 mm. The dorsal valve is gently convex,

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 497

the highest part is on the umbo, in advance of the slope to the minute
beak that terminates on the margin of the valve.

A. atticus is relatively abundant in a hard gray limestone matrix
in which the Hungata billingsi fauna occurs.

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. Billings Butte (Extinguisher) at end of west spur of
Mount Lynx, above Hunga Glacier and east of Robson Peak, Robson
Park, northwest of Yellowhead Pass, in eastern British Columbia,
Canada.

ACROTRETA DISCOIDEA, new species

Plate 100, figs. 13, 14

This form of Acrotreta is represented by three specimens of the
ventral valve that are more depressed than the ventral valve of A.
sagittalis (Salter) (Mong. 51, pl. 70, figs. 2 and 3) but unlike that
species they have a very small apical callosity and weak vascular
sinuses. The interior of the shell is marked by fine radiating lines
and a shallow, narrow depression extending from the apical callosity
to the front margin. Cardinal muscle scars small and not prominent
as in A. sagittalis and many other species. The depressed beak curves
over to the posterior margin.

The type specimen of the ventral valve has a length and width
of 3.5 mm. which give a circular outline to the margin of the valve.

One ventral valve that has the circular outline, depressed beak
and low convexity of the casts of the interior of this species has a
slight median depression on the umbo and a surface slightly roughened
by fine raised radiating lines broken by concentric lines of growth
that give the appearance of the surface of A. spinosa Walcott (Mong.
51, p. 713, pl. 79, figs. 4a, 4b) but I am not sure that spines are pres-
ent on A. discoidea. A. spinosa is an Upper Cambrian species from
the Dunderberg shale of the Eureka District of Nevada.

Formation and locality—Oczarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers quite
ferruginous. Billings Butte (Extinguisher) at end of west spur of
Mount Lynx, above Hunga Glacier and east of Robson Peak, Robson
Park, northwest of Yellowhead Pass, in eastern British Columbia,
Canada.

ACROTRETA cf. MICROSCOPICA Shumard
See Mong. U. S. Geol. Surv. No. 51, 1912, p. 693, pl. 67, figs. 1 to 10.

A small species of Acrotreta occurs in the Hungaia faunule of the
Mons formation that is about the size and form of A. microscopica

498 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

(Shumard) from Packsaddle Mountain, Texas, in strata that are
either high in the Upper Cambrian or in the Lower Ozarkian. This
form has a wide range, and what appear to be similar forms occur
in Oklahoma, Nevada, and British Columbia.

Formation and locality—Oczarkian: (211) Mons formation. Kick-
ing Horse Canyon, above second bridge on Canadian Pacific Railway,
about 1.5 miles (2.4 km.) east of Golden, British Columbia, Canada.

Genus ACROTHYRA Matthew
See Mong. U. S. Geol. Surv., No. 51, 1912, p. 715-716.

ACROTHYRA GREGARIA, new species
Plate 122, figs. 9-12

This species would be referred to Acrotreta if it were not for the
visceral area of the ventral valve (fig. 9). The dorsal valve has a
long median septum and in convexity and outline is similar to the
dorsal valve of several species of Acrotreta; the cast of the visceral
area of the ventral valve is similar to that of Acrothyra signata
Matthew (see Mong. 51, pl. 80, figs. 1a and 2). Nearly all of the
ventral valves are compressed in the hard silicious shale but a few
preserve the umbo and a beak that extends over a low area. The
dorsal valve is slightly transverse and the ventral valve a little longer
than wide.

Dimensions.—A large ventral valve has a length of 2 mm. with a
width of 1.75 mm. A dorsal valve is 2 mm. in width and nearly as
long. Large numbers of the valves are not over I mm. in diameter.

As far as known to me all the species of Acrothyra are of Middle
Cambrian age. A. gregaria is the only species from the Pacific
Province.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation. On the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast of
Burgess Pass, above Field on the Canadian Pacific Railway, British
Columbia, Canada.

Genus NISUSIA Walcott

See Mong. U. S. Geol. Surv., No. 51, 1912, p. 725, for synonymy, description
and illustration.

NISUSIA SPINIGERA, new species
Plate 100, figs. I5-I7

This is the only species of Nisusia known to me from an Upper
Cambrian formation. In outline it suggests some of the smaller shells

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 499

of Nisusia festinata (Billings) (Mong. 51, pl. 100, figs. 1a, and 1h)
from the Lower Cambrian, but it differs from that and the Middle
Cambrian species in details of area of ventral valve and outer surface.
The area of the ventral valve recalls that of N. festinata transversa
Walcott (loc. cit., fig. 4 b). The area is high and with a broad
delthyrium. The deltidium is not preserved. The outer surface (fig.
16) has long strong spines on the stronger radiating costz and fine
spines on the more delicate intermediate coste.

Dimensions.

A large fragment of a ventral valve indicates a shell
Io to 11 mm. in length with a width of 11 to 13 mm. The other three ©
specimens are much smaller.

Formation and locality—Upper Cambrian: (63x) Ottertail for-
mation. Wolverine Pass, British Columbia, 11 miles (17.6 km.)
southwest of Vermilion Pass, on the Continental Divide.

NISUSIA BURGESSENSIS, new species

Plate 110, figs. 1-8

This species differs from Nisusia alberta Walcott (pl. 111, figs. 1,
ta and Mong. 51, p. 726, pl. 100, figs. 3, 3a-d) in its somewhat finer
radiating coste and concentric lines of growth. As far as can be
determined from the compressed shells the area of the ventral valve
is also lower and the valves are smaller.

A small specimen (fig. 1) has a few long, slender, curved spines
attached to its outer margin, and older shells show small nodes on
the cost that served as the base of the spines.

The ventral valve is quite convex and the dorsal moderately so;
usually the dorsal valves are flattened and the ventral valves more or
less distorted.

Dimensions——A large dorsal valve 15.5 mm. in length has a
maximum width of 23 mm. The ventral valves are so flattened and dis-
torted by compression in the hard shale that none of them preserve
their original form.

This fine species of Nisusia is the Middle Cambrian representative
of N. festinata (Billings) (Mong. 51, pl. 100) from the Lower
Cambrian. As far as now known it occurs only with the Burgess
shale fauna near Burgess Pass.

Formation and locality —Middle Cambrian: (35k) Burgess shale
member of the Stephen formation on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess Pass, above Field, British Columbia, Canada.

500 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

NISUSIA (JAMESELLA) ORIENS, new species
Plate 110, figs. 9-14a

Among described species N. (J.) oriens may be compared in form
with N. (J.) perpasta (Pompecki) (Mong. 51, pl. 1o1, figs. I, 2,
3) from the Lower Cambrian of Bohemia, but it differs greatly in
not having strong radiating coste and an elevated apex to the ventral
valve; it also differs from all described species of Nisusia and
Jamesella in the character of the surface coste which are very fine
and but slightly elevated.

The cardinal area of the ventral valve is high and divided midway
by a large delthyrium that has a convex deltidium, but how far the
latter extends over the delthyrium has not been determined; the
cardinal area of the dorsal valve is low and divided by a broad
delthyrium that was more or less covered by a convex deltidium.

Dimensions —A large ventral valve 9 mm. in length has a maxi-
mum width of 12.5 mm., and the tongue of the median furrow extends
4.5 mm. beyond the plane of the side margin of the valve. A convex
dorsal valve 8 mm. in length has a maximum width of 12.5 mm.
Marked characters of this species are the deep, broad median sinus
with its prolonged tongue and the high area of the ventral valve, the
strongly and uniformly convex dorsal valve with its low area, and
almost entire absence of a median range. Young shells have sub-
equally convex valves and only traces of a median sinus on the ven-
tral valve.

N. (J.) oriens ranges through quite a thickness of sandstone and
arenaceous limestone about Forteau Bay.

Formation and locality—lLower Cambrian: (41d) Reddish gray
limestones of lower part of Archzocyathine zone, west side of
Forteau Bay. The species also occurs (41b) in the lower 30 feet
(9.1 m.) of the section at Forteau Point; (41c) 65 and 80 feet (19.8
and 24.3 m.) above base of Archzocyathine reef at Point Armour
on the east side of Forteau Bay, and at 41v, Schooner Cave on west
side of L’Anse au Loop.

All localities on north shore of Straits of Belle Isle, Labrador,
Canada.

Genus WIMANELLA Walcott

See Mong. U. S. Geol. Surv., No. 51, 1912, p. 745 for synonymy, description,
and illustration.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 501

WIMANELLA BOREALIS, new species
Plate 111, figs. 2-4

This shell in genera! form resembles Wimanella ? anomala from the
Middle Cambrian shales of Alabama (Mong. 51, p. 745, pl. 87, figs.
I, Ia-e). It differs in having slightly stronger radiating ribs and in
the sharper extension of the cardinal angles. Traces of the main
vascular trunks occur on the natural cast of the interior of a ventral
valve. This feature and the fine radiating ribs serve to bring the
species near to the finer ribbed species of Bullingsella.

Formation and locality —Middle Cambrian: (61v) Titkana forma-
tion; gray shaly limestone in massive beds, on west slope of Titkana
Peak, above Hunga Glacier, 3.75 miles (6 km.) northeast of summit
of Robson Peak, northwest of Yellowstone Pass, western Alberta,
Canada.

WIMANELLA OCCIDENS, new species
Plate 111, figs. 5-7

This is a rather thick calcareous shell with a smooth outer surface,
high area on the ventral valve, a strong tripartite umbonal area and a
well marked visceral area on both valves and a general outline like
that of Wimanella harlanensis (Walcott) (Mong. 51, pl. 87, figs. 5,
sa-c). It is a smaller shell than the latter and occurs well up in the
Upper Cambrian. There are a number of specimens in the collection
but none finely preserved.

Dimensions.—The average size of the ventral valve is about 10 mm.
in length by 10 mm. in maximum breadth. A dorsal valve 7.5 mm.
long has a maximum width of 1o mm.

Formation and locality—Upper Cambrian: (641) Lyell forma-
tion. Gray limestone of upper part of 1b of section. Locality: South
slope of ridge of Sullivan Peak, north side of Glacier Lake Canyon
about 0.25 mile (0.4 km.) east of foot of Southeast Lyell glacier and
about 48 miles (77.3 km.) northwest of Lake Louise Station on the
Canadian Pacific Railway, Alberta, Canada.

Genus BILLINGSELLA Hall and Clarke
See Mong. U. S. Geol. Surv., No. 51, 1912, p. 749, for synonymy, description
and illustration.

BILLINGSELLA ARCHIAS, new species
Plate 112, figs. I-5

This species is known only from more or less exfoliated biconvex
valves showing imperfectly the cast of the visceral areas and main

502 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

vascular sinuses. The interior of the ventral valve has a trifid,
umbonal cavity, and strong main vascular trunks. The interior of the
dorsal valve has an elongate visceral area with well defined lines of
advance of the anterior and posterior adductor muscle scars extending
far toward the front of the valve. Surface with fine, rounded radiat-
ing ribs with interspaces about the same width as the ribs. Shell thin,
structure unknown. The shell usually adheres to the matrix to such
an extent that only a few fragments of the outer surface are shown
by the specimens in the collection.

Dimensions.—A ventral valve Io mm. in length has a maximum
width of 10.5 mm. on the plane of the margins of the valves. +

The cardinal margin is a little shorter than the maximum width
of the valve, which gives the shell a slightly rounded outline.

Among known species B. archias recalls B. striata Walcott (Mong.
51, pl. 86, fig. 4, 4a-c) by its surface ribs, and B. exporecta Linnarsson
(Mong. 51, pl. 88, figs. 1, ta-l) by the strongly marked interiors of
the valves.

Ozarkian: (16u) Mons formation. Beds of dove gray limestones
30 inches (76.2 cm.) thick, interbedded in gray argillaceous shale.
South end of Brisco Range, north side of Sinclair Canyon about
6oo feet (182.8 m.) above the creek and 700 feet (213.3 m.) west
of Radium Hot Springs, British Columbia, Canada.

BILLINGSELLA OLEN, new species
Plate 111, figs. 8, 9

The specimens of this species are not well preserved, but they
indicate a shell with clearly defined rounded radiating ribs such as
occur on B. retroflexa (Matthew)’* and B. rominger Barrande.’ Par-
tial casts of the interior of the dorsal valve outline an umbonal cavity
and rather strong vascular sinuses that extend nearly to the anterior
margin of the valve. ;

The largest specimen, a dorsal valve, has a length of 6 mm., with
a width of 8.5 mm. at the hinge line.

*See Mong. U. S. Geol. Surv., pt. 11, 1912, pl. 90, figs. 1, 1a, 1b, and figs. 2e, 2f.

.NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 503

This is the most recent species of the genus known to me, and the
second in the Mons formation. It is in the faunule next above the
Hungaa faunule in which B. archias occurs. It differs from the
latter species in its smaller size, outline of the valves, and more
coarsely ribbed outer surface.

Formation and locality——Ozarkian: (21j}) Mons formation.
Kicking Horse Canyon above third bridge on Canadian Pacific Rail-
way, about 2.5 miles (4 km.) east of Golden, British Columbia,
Canada.

BILLINGSELLA ORIGEN, new species
Plate 121, figs. 1-3

This is a small shell with fine radiating surface coste and a well
defined median sinus on the dorsal valve. It differs from B. archias
and B. olen Walcott in being more transverse and in having finer
radiating surface coste.

Formation and locality—Ozarkian: (17t) Mons formation; in
thick layers of gray limestone near top of Mons outcrop interbedded
in hard shale; west slope of Sabine Mountain, 400 feet (121.9 m.)
above south end of Columbia Lake, 2.25 miles (3.6 km.) north of
Kootenay River Bridge, and about 2 miles (3.2 km.) northeast of
Canal Flat Station, Canadian Pacific Railway, British Columbia,
Canada.

Genus PROTORTHIS Hall and Clarke

See Mong. U. S. Geol. Surv., No. 51, 1912, p. 738, for synonymy, description
and illustration of species.

PROTORTHIS IONES, new species
_ Plate 113, figs. 1-7

All of the larger shells are more or less compressed in the some-
what shaly limestone, but from the small shells we learn that the
ventral valve was moderately convex and with the beak extending
over a rather low area the character of which is unknown. The dorsal
valve is slightly convex with a shallow median sinus gradually widen-
ing from the beak to the front ; cardinal area low with indication of a
broad delthyrium. The outline of the valves is transversely sub-
' quadrate and roughly semicircular.

Outer surface marked by fine, rather sharp radiating ribs that
increase in number towards the front by interstitial ribs coming in
between the long ribs. Shell substance fibrous and finely punctate
at least in the outer layer. An imperfect interior of the ventral valve
indicates a trifed umbonal cavity with strong main vascular sinuses

504 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

extending forward to the anterior third of the length of the valve.
The interior of the dorsal valve shows a broad, short median septum,
the impression of the posterior adductor muscle scars and the main
vascular sinuses.

Dimensions.—A ventral valve 14 mm. in length has a maximum
width of 18 mm. The proportions of the dorsal valve are the same
except it is a little shorter.

The reference of this species to Protorthis is based on its fibrous,
punctate shell, finely ribbed exterior surface, and the interior of the
dorsal valve.

A single fragmentary specimen from the upper Saskatchewan
River appears to belong to this species. It comes from a ridge on east
side of canyon 3 miles (4.8 km.) south of Wilcox Pass, North Fork
of Saskatchewan River, Alberta, Canada.

Ordovician: (162) Sarbach formation; thin-bedded dark argil-
laceous limestone in thick bands; Brisco-Stanford Range, about half
way between second and third bridges, from mouth of Sinclair
Canyon, in cliff on both sides of canyon, British Columbia, Canada.

Ordovician: (210) Sarbach formation; buff brown and gray
shaly limestone 75 feet (22.8 m.) below 21n, on low ridges southeast
of lower end of Baker Lake and Fossil Mountain about 7 miles (11.2
km.) northeast of Lake Louise Station on the Canadian Pacific
Railway, Alberta, Canada.

PROTORTHIS PORCIAS, new species
Plate 111. figs. 10-11
This species which is associated with Protorthis iones Walcott,
differs from the latter in having very fine, even and regular radiating
ribs. A small ventral valve has a strong cardinal area with an open
delthyrium, but as the beak is broken off there is no evidence of the
presence of plates closing a part of the delthyrium.
The specimens of the dorsal valve indicate that this is a more
transverse and smaller shell than P. iones.

NO. Q CAMBRIAN AND OZARKIAN BRACHIOPODA 505

Formation and locality—Ozarkian: (65w) Mons formation in 1d
of section. North side of Clearwater Canyon, 2 miles (3.2 km.)
from divide at head of canyon and about 21 miles (33.7 km.) in
an air line north, 2° west, of Lake Louise Station on the Canadian
Pacific Railway. (651) Same as 65w, but in Ic of section. (66p)
Light gray limestone of Ib of section 8.7 miles (13.9 km.) northeast
in an air line of Lake Louise Station on the Canadian Pacific Railway
at the east foot of Fossil Mountain, Alberta, Canada. (16q) Thin-
bedded gray limestone, Brisco Range, about 2 miles (3.2 km.) up
Sinclair Canyon from Radium Hot Springs on north side of canyon
near north end of 3d bridge on Banff-Windermere motor road,
British Columbia, Canada.

A specimen from the upper Saskatchewan River (67h) indicates
the presence of this species 3 miles (4.8 km.) south of Wilcox Pass,
Alberta, in cliffs of the Mons limestones.

Ordovician: (67k) Sarbach formation; gray limestone, 2.5 miles
(4 km.) from divide at head of Clearwater River Canyon, 21 miles
(33.7 km.) north, 5° west of Lake Louise Station on the Canadian
Pacific Railway. (21 0) Sarbach formation ; buff brown and gray shaly
limestone 75 feet (22.8 m.) below 2In, on low ridges southeast of
lower end of Baker Lake and Fossil Mountain, about 7 miles (11.2
km.) northeast of Lake Louise Station on the Canadian Pacific
Railway, Alberta, Canada.

P. porcias and iones Walcott are the only species found both in the
upper Mons formation of the Ozarkian and the superjacent Sarbach
formation of the Ordovician. This occurs in the Clearwater Canyon
section, also to the south, where the species is found in the Mons of
Fossil Mountain, just north of Baker Lake, and in the Sarbach of
Brachiopod Mountain on the south side of Baker Lake. The pres-
ence of a fibrous shell in the Mons is the first instance known to me
of its occurrence below the Ordovician (Canadian).

Genus EOORTHIS Walcott
See Mong. U. S. Geol. Sury., No. 51, 1912, p. 772, for synonymy, description
and illustrations.
EOORTHIS BELLICOSTATA, new species
Plate 113, figs. 8-14
In general outline and size this species is most like E. wichitaensis
(pl. 116 figs. 1-10). It differs in its uniform, regular and delicate

sharp radiating surface costee, which are beautifully preserved in the
fine, hard Burgess shale. The surface costz recall in their uniform

506 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

size and regular arrangement the coste of some specimens of Billing- -
sella coloradoensis (Shumard). See Mong. 51, pl. 85, fig. 1b.

A few casts of the interior of ventral valves show the rather
narrow cardinal area with a delthyrium of medium width and appar-
ently open, as no traces of a deltidium appeared in the compressed
shells ; a narrow, short cardinal process extends from the posterior
margin to a short distance in front of the delthyrium; teeth short and
small. The interior of the dorsal valve has a narrow cardinal area,
broad delthyrium and short cardinal process; anterior adductor
muscle scars rather large.

Dimensions.—The largest ventral valve among several hundred
specimens has a length of 13.5 mm. with a maximum width of
13.5 mm.; a dorsal valve with a length of 9.5 mm. has a maximum
width of 12.5 mm. The average shell is from 2 to 3 mm. smaller.

Formation and locality—Middle Cambrian: (35k) Burgess shale
member of the Stephen formation on the west slope of the ridge
between Mount Field and Wapta Peak, 1 mile (1.6 km.) northeast
of Burgess’ Pass, above Field, British Columbia, Canada.

EOORTHIS DESMOPLEURA (Meek)
See Mong. U. S. Geol. Surv., No. 51, 1912, p. 777, pl. 96, figs. I, 1a-7, for

synonymy, description, and illustration.

This species is strongly characterized by its “sharply defined,
slightly curved, unequal radiating plications, and finer unequal striz,
which on the central region of the valves are more or less gathered
into five or six fascicles, the middle one of which corresponds to the
sinus in the other valve” (Meek). In 1912 I illustrated one of the
type specimens of FE. desmopleura (loc. cit., pl. 96, fig. th) along
with a number of other specimens from the same general horizon
and locality. In restudying the species in connection with somewhat
similar forms from the Lower Ozarkian of Alberta, I find that two
species are figured on plate 96 of 1912 as E. desmopleura. As now
restricted the latter species is represented by figures I, Ia, 1b, Ic, Id,
Ie, Ig, Ih. Figures 11-r represent a new species E. fascigera and
figure 2, which is designated as the variety nympha of E. desmo-
pleura, is now raised to the rank of species.

With the above changes FE. desmopleura (Meek) is restricted to
localities 186, 186a, 187, 360f, as listed in 1912 (Mong. 51, p. 777),
all of which are in the Lower Ozarkian west of Colorado Springs,
Colorado. A somewhat similar form occurs at locality 30w, Notch
Peak, House, Range, Utah. With better specimens it is not improb-

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 507

able that the 30u specimens would be found to belong to some other
species.
EOORTHIS FASCIGERA, new species
Plate 117, figs. I-9
Eoorthis desmopleura (Meek), Mong. U. S. Geol. Surv., 1912, No. 51, pt. ii,
pl. 96, figs. 17 to I”.

This species was included by Walcott with Eoorthis desmopleura
(Meek), but with further study of the types of that species and the
group of shells having a more or less fasciculate arrangement of the
radiating surface ribs it becomes necessary to remove the latter from
E. desmopleura. They differ in being more transverse in outline,
uniformly smaller size, and in the peculiar grouping of the surface
radiating plications and raised lines. Usually there are four or five
sharply sloping ridges radiating from the apex to the anterior margin
of the shell, with the cardinal slopes ornamented only by the very
fine radial raised lines; these lines cover the slopes of the strong
plications and any spaces that may exist between them. The lines
are well shown on figures 1-5. Some of the specimens referred to
E. desmopleura have fascicles of sharp plications with very fine raised
lines between them but none of them are exactly similar to those
of E. fascigera.

Dimensions—A ventral valve 6.5 mm. in length has a maximum
width of 7.5 mm. Dorsal valve 6 mm. long by 8 mm. in maximum
width.

E. desmopleura occurs in the Lower Ozarkian and E. fascigera in
the Upper Cambrian where it is associated with Syntrophia rotundata
Walcott (Mong. 51, p. 804, pl. 103, figs. 4, 4a-e). The horizon
indicated is about that of the Franconia formation of Wisconsin
which carries Syntrophia primordialis Whitfield and the fine species
Eoorthis remnicha N. H. Winchell.

Formation and locality—Upper Cambrian: (14k) Deadwood
formation, Wolf Creek, Big Horn Mountains, 15 miles (24.1 km.)
west-southwest of Sheridan, Wyoming.

(168) Deadwood formation. Tepee Creek, south-southwest of
Sheridan, on road to Dome Rock, Sheridan County, Wyoming.

EOORTHIS IOPHON, new species
Plate 114, figs. 1-5; pl. 119, fig. 14
This species is one that has the general form and surface ribs and

strie of Eoorthis wichitaensis Walcott (pl. 116, figs. I-10), from
which it differs mainly in the extension of the cardinal angles.

508 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Most of the valves are evenly and gently convex but a few ventral
valves have a low mesial fold, and dorsal valves occur with a broad
and shallow mesial sinus. The radiating ribs of the outer surface
are very narrow, rounded close together and uniform in size, but
in some specimens two or three fine ribs occur between the stronger
and*more elevated ribs. (See fig. 2.)

Dimensions —The average ventral valve has a length of 8 to Io
mm. and width of 8 to 10 mm., and dorsal valve 7 to 9 mm. in length
with a width of 8 to 10 mm.

Formation and locality—Ozarkian: (65e) Mons formation.
Drift block of soft, almost granular gray limestone. Above motor
road at Ten Mile Canyon on southwest side of Sawback Range, 10
miles (16 km.) by motor road west-northwest of Banff. (67w) Gray
limestone in loose blocks on debris slope of Mons formation. South
side of Upper Ranger Brook Canyon, 10 miles (16 km.) in air line
west-northwest of Banff, and 2 miles (3.2 km.) north-northeast of
Massive Switch on Canadian Pacific Railway. (66q) Light gray
limestone, base of 1b of section. 8.7 miles (13.9 km.) northeast in
air line of Lake Louise Station on the Canadian Pacific Railway at
the east foot of Fossil Mountain, Alberta, Canada.

Mons formation: (17r) Gray limestone interbedded in shale. West
slope of Sabine Mountain 500 feet (152.4 m.) above south end of
Columbia Lake, 2 miles (3.2 km.) north of Kootenay River Bridge
and about 2 miles (3.2 km.) northeast of Canal Flat Station on
Canadian Pacific Railway. (21d) Argillaceous shale and thin layers
of dense gray limestone. Northern end of Stanford Range on south-
east side of Sinclair Canyon just below Radium Hot Springs Pool,
British Columbia, Canada.

EOORTHIS LINEOCOSTA, new species
Plate 115, figs. 3-5

This is one of the largest of the Ozarkian species of Eoorthis.
The valves are gently convex with a shallow sinus on the dorsal valve.
It differs from E. desmopleura by its straight, fine ribs that radiate
from the umbo just above the apex of the valves to the outer margin.
A few fine ribs arise between the long ribs and extend to the front
margin. This surface is more like that of Eoorthis tophon (pl. 114,
fig. 1) than any other species from the Lower Ozarkian known to me.

Dimensions.—A ventral valve 12 mm. in length has a maximum
width of 14.5 mm. The dorsal valve is from 1 to 1.5 mm. shorter
in length than the ventral valve.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 509

Formation and locality —Oczarkian: (360a) Manitou formation.
Red silicious limestone on west side of Trout Creek below Bergen
Park, 7 miles (11.2 km.) north-northwest of Manitou, El Paso
County, Colorado.

EOORTHIS OCHUS, new species
Plate 117, figs. 10-13

This species is the representative of Eoorthis desmopleura (Meek)
which occurs in the Ozarkian of Colorado, Utah, Montana, etc.” It
differs in having more regularly arranged sharp ribs that have
uniform fine, radiating, elevated striz on their slopes, the strize also
extending over the cardinal slope on the postero-lateral surface of the
valves. The ribs and elevated striez of E. desmopleura are not only
more irregular in arrangement and number but also less prominent ;
one example, however, has very regular strong ribs but the elevated
striz are absent. E. ochus is a larger shell than E. fascigera Wal-
cott (pl. 117 figs. I-g) and its ribs and elevated strie are more
regular in distribution and character. It has developed the sharp
radiating surface fascicles farther than in EF. fascigera; is less
transverse in outline of its valves, and occurs in a considerably
higher horizon,

Formation and locality—Ozarkian: (16u) Mons formation, south
end of Brisco Range, north side of Sinclair Canyon about 600 feet
(182.8 m.) above the creek and 700 feet (213.3 m.) west of Radium
Hot Springs, British Columbia, Canada.

(67t) Gray limestone 2e of section. Southeast side of Douglas
Lake Canyon Valley, 12.75 miles (20.5 km.) east, 5° north of Lake
Louise Station on the Canadian Pacific Railway, Alberta, Canada.

EOORTHIS PUTILLUS, new species
Plate 114, figs. 6, 7; pl. 115, fig. 9

There is a wide variation in the strength and character of the
radiating ribs of the shells referred to Eoorthis desmopleura (Meek)
by Walcott (Mong. 51, U.S. Geol. Surv., pl 96). With the accumu-
lation of material from widely separated localities some of the
variations may be grouped as indicating distinct species and varieties.
One of these that resembles the plano-convex small shells of E. des-
mopleura, occurs in large numbers in a layer of limestone of the
Chushina formation. Among these, ventral valves average 5.5 to

*See Mong. 51, U. S. Geol. Surv., pt. 1, 1912, p. 777-778.

510 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

6.5 mm. in length and width and the dorsal valves 5 to 6 mm. in
length and 5 to 6.5 mm. in maximum width. A few are larger and
some below the average. None of them equal the size of the type
specimens of EF. desmopleura.

The surface of E. putillus is marked by sharply defined radiating
plications that increase in number by the intercalation of additional
ribs between the main ribs that originate on the umbo just in advance
of the beak. The ribs or plications are grouped in fascicles on the
central portion of the valves. A shallow median sinus occurs on the
dorsal valve and a strong median fascicle of ribs represents a median
fold on the ventral valve. There is considerable variation in the
strength of the plications or ribs on different shells but all of them
are sharp when on a well preserved surface.

When imperfect or abraded the young shells of E. wichitaensis
Walcott may be mistaken for this species and it is often difficult to
decide to which species many of the shells should be referred. £.
putillus represents a widely distributed species in the Cordilleran
area. On the north it occurs in the Mt. Robson District (61q)
and to the south in British Columbia it occurs in the Lower Mons
fauna (16q) of Sinclair Canyon. It is represented at the following
localities.

Formation and locality—Ozarkian: (61q) Chushina formation.
Gray limestone in beds of varying thickness, one or two layers
quite ferruginous. In Billings Butte (Extinguisher) at end of west
spur of Mount Lynx, above Hunga Glacier and east of Robson
Peak, northwest of Yellowhead Pass, in eastern British Columbia,
Canada.

Mons formation: (65f) Hard, light gray limestone, upper por-
tion of ta of section. Block that fell from cliff above southeast
Lyell Glacier, about 50 miles (80.4 km.) northwest of Lake Louise
Station on the Canadian Pacific Railway. (67w) Gray limestone in
loose blocks on slope of Mons formation. South side of Upper
Ranger Brook Canyon, 10 miles (16 km.) in air line west-northwest
of Banff, and 2 miles (3.2 km.) north-northeast of Massive Switch
on Canadian Pacific Railway. (21m) Thick-bedded hard dove
colored limestone. On side of brook .5 mile (.8 km.) below Baker
Lake at east base of Brachiopod Mountain and east-southeast of
Fossil Mountain, 8 miles (12.8 km.) northeast in an air line of Lake
Louise Station on the Canadian Pacific Railway. (21m’) Thick-
bedded hard dove colored limestone 21 feet (6.4 m.) below 21 m.
On side of brook .5 mile (.8 km.) below Baker Lake and east-

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 511

southeast of Fossil Mountain, 8 miles (12.8 km.) northeast in an air
line of Lake Louise Station on the Canadian Pacific Railway.

(16v) Soft gray thin-bedded limestone. Brisco Range north side
of Sinclair Canyon about 75 feet (22.8 m.) above the creek just below
the fourth bridge on the Banff-Windermere motor road, which is
4 miles (6.4 km.) above the first bridge.

Mons formation: (16y) Compact gray limestone crowded with
broken fossils. Brisco Range, north side of Sinclair Canyon about
500 feet (152.4 m.) above stream on edge of cliff and about 400 feet
(121.9 m.) up the canyon from the first bridge west on Banff-Win-
dermere motor road. (16y’) Compact gray limestone crowded with
broken fossils from 25 to 30 feet (7.6 to 9.1 m.) above 16y. Brisco
Range, north side of Sinclair Canyon about 500 feet (152.4 m.) above
stream on edge of cliff and about 400 feet (121.9 m.) up the canyon
from the first bridge west on the Banff-Windermere motor road.
(21e) Gray thin-bedded limestones. South end of Brisco Range on
northeast side of Sinclair Canyon about 800 feet (243.8 m.) up the
canyon from the first bridge west on the Banff-Windermere motor
road. (21f) Hard gray limestone interbedded in shale. North end
of Stanford Range on southeast side of Sinclair Canyon, 180 to 200
feet (54.8 to 60.9 m.) above first bridge from mouth of canyon,
British ‘Columbia, Canada.

A variety closely related to this species occurs at several localities.

Mons formation: (17n) Thin layer gray nodular limestone inter-
bedded in argillaceous shale. North side of Stoddart Creek Canyon
‘near its mouth, six miles (9.6 km.) south of Sinclair Canyon, Stan-
ford Range, on east side of Columbia River Valley. (211) Thin-
bedded gray limestone interbedded in shale. Kicking Horse Canyon
above second bridge on Canadian Pacific Railway about 1.6 mile (2.6
km.) east of Golden. (21j) Hard gray limestone interbedded in shales.
Kicking Horse Canyon above third bridge on Canadian Pacific Rail-
way, about 2.25 miles (3.6 km.) east of Golden, British Columbia,
Canada.

EOORTHIS PUTILLUS LAEVIUSCULA, new variety
Plates; figs. 1, 2

This shell averages smaller than E. putillus and differs from it in
having somewhat finer surface ribs or coste, and may be considered
a finely ribbed variety of the species, although some of the smaller
shells of the latter closely resemble it.

Formation and locality. Ozarkian: (67q) Mons formation. Com-
pact gray limestone 200 feet (60.9 m.) from top of Ia of section.

512 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Southeast side of head of Douglas Lake Canyon Valley, 12.75 miles
(20.5 km.) east, 5° north of Lake Louise Station on the Canadian
Pacific Railway, Alberta, Canada.

(17y) Mons formation; west slope Stanford Range, east side of
Columbia River Valley, 5 miles (8 km.) south of Sinclair Canyon and
.5 mile (.8 km.) north of Stoddart Creek, British Columbia, Canada.

A very closely allied shell occurs at locality (16y), Mons formation.
Compact gray limestone crowded with broken fossils. Brisco Range,
north side of Sinclair Canyon about 500 feet (152.4 m.) above
stream on edge of cliff and about 400 feet (121.9 m.) up the canyon
from the first bridge west on Banff-Windermere motor road. (17x)
Gray finely granular limestone. West slope of Stanford Range,
east side Columbia River Valley, 5.25 miles (8.4 km.) south of
Sinclair Canyon and .25 mile (.4 km.) north of Stoddart Creek.
Both in British Columbia, Canada.

EOORTHIS VICINA, new species
Plate 112, figs. 6-9

This is the Lower Ozarkian representative of E. fascigera (ante
p. 507) of the subjacent Upper Cambrian. Both species have about
the sare range of variation in the gathering of the fine radiating ribs
into fascicles except that in E. vicina the fascicles are depressed and
less prominent and the average shells are much longer. The valves
are rather uniformly and moderately convex and with only a slight
mesial fold on the ventral valve and a slight flattening represents the
mesial sinus on the dorsal valve.

Dimensions.—A ventral valve 7.5 mm. in length has a maximum
width of 9mm. A dorsal valve 8 mm. in length has a maximum width
of 10.5 mm.

Formation and locality —Oczarkian: (65x) Lower portion of Mons
formation, If of section in a gray limestone. North side of Clear-
water Canyon, 2 miles (3.2 km.) from divide at head of canyon and
about 21 miles (33.7 km.) in an air line north, 2° west, of Lake
Louise Station on the Canadian Pacific Railway. (67w) Loose blocks
of light gray limestone in slopes beneath cliff of Mons formation.
South side of Upper Ranger Brook Canyon, 10 miles (16 km.) in
air line west-northwest of Banff, and 2 miles (3.2 km.) north-
northeast of Massive Switch on Canadian Pacific Railway, Alberta,
Canada.

(16u) Mons formation. Beds of dove gray limestone 30 inches
(76.2 cm.) thick, interbedded in gray argillaceous shale. South end

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 513

of Brisco Range, north side of Sinclair Canyon about 600 feet
(182.8 m.) above the creek and 700 feet (213.3 m.) west of Radium
Hot Springs, British Columbia, Canada.

EOORTHIS WICHITAENSIS Walcott
Plate 116, figs. I-10

See Mong. U. S. Geol. Surv., No. 51, 1912, p. 790, pl. 94, figs. 1, 1a-o, for
synonymy, description, and illustration.

This species is widely distributed and has a considerable range of
variation in outline and convexity of the valves and surface ribs
and striz. It is probable that a detailed study of large collections
from various localities and stratigraphic zones of the Upper Cam-
brian and Lower Ozarkian would result in recognizing some varia-
tions as typical of certain stratigraphic zones. Such a study is needed
not only for this species but for all species and in many cases genera
of the Cambrian and Lower Ozarkian faunas.

By an error the specimen represented by figure 1, plate 94, of Mong.
51, was designated as the type of this species although it is more
like E. indianola Walcott (pl. 97, figs. 2, 2a-b) in having a high
apex andvin the character of its rounded surface ribs. In view of this
I wish to designate figure 1f, plate 94, as having the typical form and
surface of FE. wichitaensis. The same type of surface is shown by
figures 1b, Id, le, Ig, 1h, 11. On figures 1, Ia, Ic, the fine radiating
ribs are uniform and close together. On figure Id stronger ribs
occur and this feature is increased on figures Ie-n. The almost
smooth, finely ribbed variety of surface represented by figures IP,
Iq, I”, Is is designated as the variety Jaeviuscula (Mong. 51, descrip-
tion of pl. 94).

Shells that appear to be identical with or closely related to O.
wichitaensis Walcott occur at the following localities in Alberta:

Upper Cambrian.—Lyeli formation: (641) Head of Glacier Lake
Canyon Valley about 2 miles (3.2 km.) above head of lake. Cliff on
north side next to moraine of ice foot of Southeast Lyell glacier ;
about 48 miles (77.2 km.) northwest of Lake Louise Station on the
Canadian Pacific Railway, Alberta, Canada.

(66m) Sawback Range, second canyon northwest of Mount Edith,
4.75 miles (7.6 km.) west-northwest of Banff. (64t) Sawback
Range, Ranger Brook Canyon, 10 miles (16 km.) in air line north-
northwest of Banff, and 2 miles (3.2 km.) north-northeast of Massive
Switch, on Canadian Pacific Railway, Alberta, Canada.

514 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Ozarkian.—The Ozarkian form of this species is similar in average
size, surface markings, and outline to the Upper Cambrian specimens,
but it scarcely seems probable that the species has so great a vertical
range in the formations and that it is the only surviving species of the
Upper Cambrian Lyell fauna far up in the Mons formation. On this
account I call attention to its presence in the Mons with considerable
doubt as to its actual identity with E. wichitaensis.

(66q) Mons formation, in 1b of section. 8.7 miles (13.9 km.)
northeast in air line of Lake Louise Station on the Canadian Pacific
Railway, at the east foot of Fossil Mountain, Alberta, Canada.

(17r) West slope of Sabine Mountain, 500 feet (152.4 m.) above
south end of Columbia Lake, 2 miles (3.2 km.) north of Kootenay
River Bridge and about 2 miles (3.2 km.) northeast of Canal Flat
Station on the Canadian Pacific Railway, British Columbia, Canada.

Genus FINKELNBURGIA Walcott
See Mong. U. S. Geol. Surv., No. 51, 1912, p. 793.

FINKELNBURGIA NOBLEI, new species
Plate 115, figs. 6, 6a, 7, 8, 8a

Of this species we have portions of the exterior of the valves, two
casts of the interior of the ventral valve and fragments of the cast
of the interior of a dorsal valve.

The shell was relatively thick with the outer surface marked by
fine flattened radiating coste outlined by sharp, very narrow incised
lines ; the costee vary from .5 to .75 mm. in width on the central por-
tions of the shell.

A ventral valve 20 mm. in width has a length of 10 mm. and a
depth at the umbo of 5 mm. The cast of the interior of the ventral
valve shows a strongly defined umbonal cavity (pseudospondilium)
and two strong vascular trunks. A fragment of a cast of the interior
of the dorsal valve has the impression of the two anterior adductor
muscle scars and the cast of the bases of the main vascular sinuses.

F’, noblei is a larger shell than either F. finkelnburgia or F. oseola
Walcott (Mong. 51, pl. 93). Its transverse outline recalls that of
F. oseola but it differs from the latter in details of the interior of
the valves and exterior surface.

Formation and locality——Upper Cambrian: (73c) Muav forma-
tion. Hard gray limestone 200 feet (60.9 m.) above the base. Her-
mit Creek, Bright Angel Quadrangle (U.S. G. S.), Grand Canyon
of the Colorado River, Arizona.

NOG CAMBRIAN AND OZARKIAN BRACHIOPODA 515

SYNTROPHIDZ

The family Syntrophid@ is represented in the Cordilleran area by
the following genera and species :*
Swantonia meeki Walcott (Mong. 51, p. 797) Lower Cambrian

Syntrophia cambria Walcott ( “ “ p.800) Middle Cambrian
* nundina Walcott ( “ “ p.802) Ozarkian
2 ? unsia Walcott ( “ “ p.804) Middle Cambrian
: isis Walcott (loc. cit. p2517) Ozarkian
ss nisis Walcott Cae ee pe Sia) a
“ nonus Walcott (wm. #7.) Ep: HIS) A
. perilla Walcott (Gita) --pi.5ioy .

Huenella abnormis Walcott (Mong. 51, p. 805) Upper Cambrian
= icetas Walcott (loc. cit. p.520) Ozarkian
oh juba Walcott (oh) Sit) sor) Ozarldan
i. hera Walcott ( “ “ ».520) Upper Cambrian
ee lesleyi Walcott (Mong. 51, p. 807) Ozarkian
simon Walcott Coe ett: ps 521) %
3 texana Walcott ( “ “ p.522) Upper Cambrian
‘ ? weedi Walcott ( p. 522) z *

Clarkella montanensis Walcott (Mong. 51, p. 810) Ozarkian

For genera and species from other localities see Cambrian Brachio-
poda, 1912.” ,

Genus SYNTROPHIA Hall and Clarke
Synonymy. See Mong. U. S. Geol. Surv. No. 51, 1912, p. 798.

In referring to this genus in 1912 I wrote: “ The Cambrian type
of Syntrophia is S. rotundata Walcott of the Upper Cambrian. It
has a spondilium in each valve supported by a median septum, and
a short area divided by a large open delthyrium.”’ A second species
was described and illustrated, S. alata Walcott, which has a similar
structure. Several other species, notably S. calcifera Billings, were
referred to Syntrophia on account of their external form, and in the
case of S. calcifera the apparent evidence in one of the types (Mong.
51, pl. 104, fig. 1b) of a spondilium and median septum. Several spe-
cies were found to have a pseudospondilium attached directly to the
inner surface of each valve and at the same time to have a more or
less radially plicated or ribbed surface; for these the genus Huenella
was proposed (loc. cit., p. 805) and seven species referred to it,
H. texana being selected as the genotype. This species has a wide
range in the radial plication of its surface on both valves. They may

Reference to Mong. U. S. Geol. Surv., No. 51, 1912, will be indicated in this
list by Mong. 51 and page, and to this paper by Joc. cit. and page.
* Mong. U. S. Geol. Surv. No. 51, 1912, pp. 796-810

516 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

be covered with plications (Mong. 51, pl. 103, fig. 1e) or they may
have a few (figs. 1f, 19) or only a single plication (fig. Ic). Another
species H. abnormis Walcott (Mong. 51, pl. 103, figs. 2, 2a-e) has a
similar variation in surface character. This variation from the com-
pletely plicated or ribbed surface to the smooth shell has made it
very difficult to assign the smooth surfaced species to either genus
with certainty if the interior of the valves is unknown. I referred
several of them to Synthrophia (Mong. 51, pp. 798-804) but with the
discovery of interiors showing a pseudodeltidium they should be
referred to Huenella or, if a new genus is to be created for the
smooth nonplicate shells, to that new genus. At present I am not
prepared to propose such a genus. Specimens of Huenella texana with
a smooth surface largely predominate in a limestone from Cold Creek
Canyon, Texas, (Loc. 71) while the plicated surface predominates
among the shells from the limestone of Pack Saddle Mountain (Loc.
68). For the smooth shells I proposed the name of H. texana laevius-
cula (Mong. 51, p. 808) but this name would equally well apply
to the smooth shells from other localities where the plicated shells
predominate. Among other species Camerella calcifera Billings
(Mong. 51, p. 800, pl. 104, figs. 1, Ia-i) appears to be a smooth form
of Huenella but one of the type specimens and a transverse section
cut across in front of the beak appears to show a septum supporting
a spondilium.

The new species described in this paper and referred to Syntro-
phia may be smooth surface forms of Huenella but this cannot now be
determined.

SYNTROPHIA cf. CALCIFERA

Syntrophia calcifera (Billings), see Mong. U. S. Geol. Surv., No. 51, 1912,
p. 800, pl. 104, figs. 1, 1a-1.

A number of specimens of a species of Syntrophia that cannot be
readily separated from typical forms of S. calcifera occur in the
central portion of the Mons formation. The species is referred to
the Lower Ordovician in Monograph 51, but at present it is referred
to the Ozarkian as defined by Ulrich.

Formation and locality—Ozarkian: (16u) Mons _ formation.
Dove gray limestone on north side of Sinclair Canyon, 600 feet
(182.8 m.) above the creek and 700 feet (213.3 m.) west of
Radium Hot Springs.

(16y) Compact gray limestone, Sinclair Canyon, 500 feet (152.4
m.) above stream on edge of cliff and about 400 feet (121.9 m.) up the
canyon from the first bridge west on Banff-Windermere motor road.

NO. Q CAMBRIAN AND OZARKIAN BRACHIOPODA Bue,

(21e) Gray, thin-bedded limestones, Sinclair Canyon, about 800
feet (243.8 m.) up the canyon from the first bridge west on Banff-
Windermere motor road. South end of Brisco Range, British Co-
lumbia, Canada.

SYNTROPHIA ISIS, new species
Plate 117, figs. 14-17

The general form of the valves is much like that of Syntrophia
campbelli Walcott and S. rotundata Walcott (Mong. 51, p. 801 and pl.
103, figs. 4, 4a-c) except that the mesial fold of the dorsal valve
extends from near the beak to the front margin and the ridges on the
side of the mesial furrow of the ventral valve are much stronger, in
this respect resembling the dorsal valve of Huenella billingst Walcott
(Mong. 51, pl. 102, figs. 5, 5a, b).

Dimensions.—A ventral valve 5.5 mm. in length on the median line
has a maximum width of 6.25 mm. Dorsal valve 7 mm. long on the
median line has a maximum width of 9 mm. Measurements on plane
of the margins of the shell.

S. isis is fairly abundant and it occurs in the Cordilleran area from
Glacier Lake southeast for 49 miles (78.8 km.) where it is found at
Fossil Mountain and also at Ranger Canyon in the Sawback Range.

Formation and locality—Oczarkian: (65f) Mons formation (Up-
per) in hard light gray limestone, upper portion of Ia of section.
Block that fell from cliff above southeast Lyell Glacier, about 50
miles (80.4 km.) northwest of Lake Louise Station on the Canadian
Pacific Railway. (660) Light gray limestone 1a of section 10 feet
(3.0 m.) from top. 8.7 miles (13.9 km.) northeast in air line of
Lake Louise Station on the Canadian Pacific Railway at the east foot
of Fossil Mountain. (64y) Sawback Range, Ranger Brook Canyon,
10 miles (16 km.) in air line west-northwest of Banff, and 2 miles
(3.2 km.) north-northeast of Massive Switch, on Canadian Pacific
Railway, Alberta, Canada.

A closely related form occurs at locality 16u, Mons formation ; beds
of dove gray limestone 30 inches (76.2 cm.) thick, interbedded in gray
argillaceous shale. South end of Brisco Range, north side of Sinclair
Canyon about 600 feet (182.8 m.) above the creek and 700 feet
(213.3 m.) west of Radium Hot Springs, British Columbia, Canada.

SYNTROPHIA NISIS, new species
Plate 110, figs. 1-3

This species is strongly characterized by having a median groove
on the mesial fold of the dorsal valve, in this respect resembling

518 . SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Huenella billingsi Walcott (Mong. 51, pl. 102, fig. 5c). The ventral
valve has a deep broad mesial furrow that starts very near the apex
of the valve and extends to the front margin.

This species is rare at Fossil Mountain and has not been recognized
elsewhere.

Dimensions.—The largest dorsal valve has a length of 7 mm. on the
median line; maximum width 9 mm., with a convexity of about 3.5
mm. Measurements on plane of the margin of the shell.

Formation and locality —Ozarkian: (660) Mons formation (Up-
per) in light gray limestone of Ia of section, 10 feet (3 m.) from top.
8.7 miles (13.9 km.) northeast in air line from Lake Louise Station
on the Canadian Pacific Railway at the east foot of Fossil Mountain,
Alberta, Canada.

SYNTROPHIA NONUS, new species
Plate 110, figs. 4-9

S. nonus is a relatively broad transverse form with a short anterior
median fold on the dorsal valve and a rather shallow mesial furrow
on the ventral valve. The valves are less convex than those of S. isis,
S. perilla and S. nisis, in this respect resembling the Ordovician species
S. lateralis (Whitfield) (Mong. 51, pl. 102, figs. 6a-e).

Dimensions —The largest dorsal valve has a length of 7 mm. and a
maximum width of g mm. Another dorsal valve is 5.75 mm. in
length with a maximum width of 7.75 mm. A ventral valve with a
maximum width of 11.5 mm. has a length of 7 mm. Measurements
on the plane of the margins of the shell.

The short mesial fold of the dorsal valve is not unlike that of S.
nundina Walcott (Mong. 51, pl. 102, fig. 4a) but it differs from the
latter species in its transverse outline and less convex valves.

Formation and locality—Ozarkian: (660 and 66n) Mons forma-
tion (Upper) in light gray limestone. 8.7 miles (13.9 km.) northeast
in air line from Lake Louise Station on the Canadian Pacific Railway
at the east foot of Fossil Mountain. (21m, 21m’) Thick-bedded hard
dove colored limestone. On side of brook .5 mile (.8 km.) below
Baker Lake at east base of Brachiopod Mountain and east-southeast
of Fossil Mountain, 8 miles (12.8 km) northeast in an air line of Lake
Louise Station on the Canadian Pacific Railway. (67t) Gray lime-
stone, 2e of section, southeast side of head of Douglas Lake Canyon
Valley, 12 miles (19.3 km.) east, 5° north, of Lake Louise Station
on the Canadian Pacific Railway, Alberta, Canada.

(16y’) Mons formation. Compact gray limestone crowded with
broken fossils. Brisco Range, north side of Sinclair Canyon about

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 519

500 feet (152.4 m.) above stream on edge of cliff and about 400
feet (121.9 m.) up the canyon from the first bridge west on the
Banff-Windermere motor road, British Columbia, Canada.

(17x) Mons formation. Gray finely granular limestone. West
slope Stanford Range, east side Columbia River Valley, 5.25 miles
(8.4 km.) south of Sinclair Canyon and .25 mile (.4 km.) north of
Stoddart Creek, British Columbia, Canada.

SYNTROPHIA PERILLA, new species
Plate 118, figs. 1-7

This is the largest and most abundant species of Syutrophia known
to me from the Mons formation. It suggests S. calcifera (Billings)
(Mong. 51, pl. 104, fig. I, Ia-7) in some of its variations and like
that species it changes greatly in convexity and outline from the young
to its mature stage. This is most marked in the increase of convexity
of the valves and the development of the mesial fold and sinus. The
older and large shells are rare in the collection, while the young and
smaller shells occur in, large numbers.

Diumensions.—A large dorsal valve has a length on the median
line of 13 mm., with a maximum width of 15.5 mm. A large ventral
valve is 14.5 mm. long on the median line and 12.5 mm. in maximum
width. Measurements on the plane of the margins of the shell.

Formation and locality—Ozarkian: (65x) Mons _ formation
(Lower), 1f of section. North side of Clearwater Canyon, 2 miles
(3.2 km.) from divide at head of canyon and about 21 miles (33.7
km.) in an air line north, 2° west, of Lake Louise Station on the
Canadian Pacific Railway. (66n) Thin-bedded gray limestone, 1a of
section 255 feet (77.7 m.) from summit of Mons. 8.7 miles (13.9
km.) northeast in air line of Lake Louise Station on the Canadian
Pacific Railway at the east foot of Fossil Mountain, Alberta, Canada.

Shells that appear to be identical with this species occur in the
Mons formation, Sinclair Canyon section (16q), and in the upper
portion of the Upper Cambrian (64u, 64v) its presence is suggested
by three rather small ventral valves.

(16q) Ozarkian: Mons formation. Thin-bedded gray limestone.
Brisco Range, about 2 miles (3.2 km.) up Sinclair Canyon from
Radium Hot Springs on north side of canyon near north end of
3d bridge on “Banff-Windermere motor road and about 15 miles
(24.1 km.) from Lake Windermere in Columbia River Valley,
British Columbia, Canada.

(64u, v.) Upper Cambrian: Lyell formation Sawback Range, at
head of northeast branch of Ranger Brook Canyon, Io miles (16

520 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

km.) north-northwest of Banff and 3 miles (4.8 km.) north-northeast
of Massive Switch on Canadian Pacific Railway, Alberta, Canada.

Genus HUENELLA Walcott
Huenella Walcott, 1908. See Mong. U. S. Geol. Surv., No. 51, p. 805.

Huenella differs from Syntrophia in having a more or less radial
plicate surface and a sessile pseudospondilium instead of a free spon-
dilium supported on a median septum.

There appear to be two species: from the typical Mons formation
and two that may be from the Upper Cambrian Lyell formation.

The fine ridges or raised lines on the surface of the two species
may mean that they represent a genus distinct from Huenella. This
type of outer surface is unknown to me on any of the species of
Syntrophia.

HUENELLA HERA, new species
Plate 1109, fig. 10

This species is represented by a specimen of the exterior and a
natural cast of the ventral valve; it is moderately convex with a
strong sinus that at the front is a little wider than the greatest width
of the valve; a slight rounded ridge occurs on each side of the sinus
and a few low narrow plications occur on the outer slopes and in the
sinus. The general appearance of the valve is not unlike that of
some ventral valves of H. texana Walcott and H. abnormis except
that it is shorter and more transverse. The shell is exfoliated near the
apex so as to show a cast of the pseudospondilium.

Dimensions —Length 7 mm., maximum width 8 mm., measured
on the plane of the margin of the valves.

Compared with other species this ventral valve approaches in form
that of H. simon (pl. 118), but it is more transverse in outline and
the surface plications are much stronger. It is more like some varieties
of H. texana in its plications.

Formation and locality—Upper Cambrian: (64w) Lyeil forma-
tion. Drift blocks of limestone. Sawback Range, Ranger Brook
Canyon, 10 miles (16 km.) in air line west-northwest of Banff, and
2 miles (3.2 km.) north-northeast of Massive Switch on Canadian
Pacific Railway, Alberta, Canada.

HUENELLA ICETAS, new species
Plate 120, figs. 1-3

This species is characterized by a deep, broad median sinus on the
ventral valve and a rather acutely ridged mesial fold on the dorsal

NO. 9 . CAMBRIAN AND OZARKIAN BRACHIOPODA 521

valve that extends from near the posterior margin to the front
margin. The surface is marked by about 14 narrow fine radiating
ridges each side of the mesial fold of the dorsal valve and slight
traces of similar ridges on the mesial fold. The entire surface of the
ventral valve is marked by fine radiating ridges similar to those on the
dorsal valve.

Dimensions—A dorsal valve 7.5 mm. in length has a maximum
width of 9.5 mm. and a ventral valve 7 mm. long has a maximum
width of 9 mm., measured on the plane of the margins of the valves.
There is considerable range in the proportions of length and breadth
between the young and old shells, also in the strength of the mesial
fold and sinus.

The ventral valve may be compared with that of H. hera (pl. 1109,
fig. 10) and the dorsal with that of H. orientalis Walcott (Mong. 51,
pl. 104, figs. 3a, b).

Formation and locality—Ozarkian: (65e) Mons formation
(Lower) in soft, almost granular gray limestone. Above motor road
at Ten Mile Canyon on southwest side of Sawback Range, 10 miles
(16 km.) by motor road west-northwest of Banff, Alberta, Canada.

HUENELLA JUBA, new species
Plate 119, figs. 11-13

This species is characterized by the alate postero-lateral angles
of the valves and strong mesial fold and sinus. The outer surface
is marked by many fine radiating ridges or raised lines.

The largest shell is represented by a ventral valve 8.5 mm. in
length with a width at the hinge line of 19 mm.

Formation and locality—Ozarkian: (65e) Mons formation
(Lower) in soft, almost granular gray limestone. Above motor road at
Ten Mile Canyon on southwest side of Sawback Range, Io miles
(16 km.) by motor road west-northwest of Banff, Alberta, Canada.

(17t) Mons formation. Thick layers of gray limestone near top
of Mons outcrop, interbedded in hard shale. West slope of Sabine
Mountain 400 feet (121.9 m.) above south end of Columbia Lake,
and 2.25 miles (3.6 km.) north of Kootenay River Bridge and about
2 miles (3.2 km.) northeast of Canal Flat Station, Canadian Pacific
Railway, British Columbia, Canada.

HUENELLA SIMON, new species
Plate 118, figs. 8, 9

This species is based on a ventral valve that has the outline of
H. icetas (pl 120, figs.1-3.) It differs in having in shells of similar

522 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

size a broad, shallow mesial sinus instead of a deep, broad sinus.
Surface marked by many radiating fine ridges or raised lines.

Dimensions—A ventral valve has a maximum width of 10.5 mm.
and a length of about 9 mm.

Formation and locality—Upper Cambrian: (64z) Lyell forma-
tion in drift blocks of limestone. Ten Mile Canyon above motor
road on southwest side of Sawback Range, 10 miles (16 km.) by
motor road west-northwest of Banff, Alberta, Canada.

HUENELLA TEXANA Walcott
Plate 120, figs. 4, 6, 7, 8

Camerella sp. ? Shumard, 1861, Am. Jour. Sci., 2d ser., vol. 32, p. 221.

Syntrophia texana Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28 p. 204.

Since the publication of ‘‘ Cambrian Brachiopoda” (Mong. U. S.
Geol. Surv., No. 51, 1912) two small slabs of limestone collected
by Dr. Walter H. Weed have come to hand on which there are
a number of beautifully weathered-out valves of this species. These
include about the same range of variation in form and outer surface
as for H. texana, and there are also a number of interiors showing
the pseudospondilium, one of which is illustrated in figure 6. Com-
parison should be made between the illustrations of this species as
it occurs in Texas (Mong. 51, pl. 103, figs. 1, 1a-7) and those from
Wyoming.

Dimensions.—The average length of the Wyoming shells is about
7 mm. and maximum width 8.5 mm., measured on the plane of the
margins of the valves. This is about the size of the specimens from
Texas. ;

Formation and locality—Upper Cambrian: (302g) Gallatin for-
mation. Limestone on north slope of Crowfoot Ridge, south of
Gallatin Valley, Yellowstone National Park, Wyoming.

On the same surface with H. texana a number of specimens of
a finely ribbed species of Huenella occur, to which I have given the
name H. weedi.

HUENELLA ? WEEDI, new species
Plate 120, figs. 5,7, 8

This species occurs more or less abundantly weathered in relief
on the surface of gray limestone in association with Huenella texana
Walcott. The valves are less convex than those of H. tesana, in this
respect resembling those of H. simon (pl. 118, figs. 8,9). The outer
surface is similar to that of some specimens of Eoorthis, E. wichi-
taensis Walcott in having sharp narrow raised radiating ribs with

NO. Q CAMBRIAN AND OZARKIAN BRACHIOPODA 523

one or more intercalated ribs between them. The type of surface
also occurs in HZ. juba (pl. 1109, fig. 13) and H. icetas (pl. 120, figs.
rake

Dimensions —A large, somewhat crushed ventral valve has a
length of 8 mm. and a maximum width of 11.5 mm. A dorsal valve
8 mm. in length has a maximum width of 10.5 mm., measured on
the plane of the margins of the valves.

Formation and locality—Upper Cambrian: (302g) Gallatin for-
mation. Limestone on north slope of Crowfoot Ridge, south of
Gallatin Valley, Yellowstone National Park, Wyoming.

BRACHIOPODS FROM ISLAND OF NOVAYA ZEMLYA, RUSSIA

Dr. Olaf Holtedahl announced in 1922 the discovery by a Nor-
wegian scientific expedition led by him, of an “ Upper Cambrian
Fauna of Pacific Type in the European Arctic Region” near the
west coast of the southern island’of Novaya Zemlya on the peninsula
between Bessimyanni and Gribovii Fjords.” He noted the presence
in the collections of several species of brachiopods and trilobites and
correlated them with forms from western North America. Subse-
quently he sent the collection to me for examination and description.

The rock containing the specimens was carefully broken up in
order to secure all the material possible for study. It was soon dis-
covered that the brachiopods were related to species from the lower
Ozarkian Mons fauna of the Cordilleran Province, and the trilo-
bites were of post-Cambrian age. The entire fauna will be published
in a report of the expedition. Meantime Dr. Holtedahl very kindly
gave me permission to publish the brachiopods in this paper.

The brachiopods include: Lingulella cf. desiderata Walcott, L.
artica n. sp., Acrotreta sp. undt., Obolus (Westonia) sp. undt., Bill-
ingsella holtedahli n. sp., B. ? oppius n. sp., Eoorthis sabus n. sp.,
Huenella triplicata n. sp. All of these have their representatives in
the Upper Cambrian, also in the lower Ozarkian.

Most of the associated trilobites are distinctly of a Lower Ozarkian
type and some may belong higher in the series.

Sub-genus WESTONIA Walcott
OBOLUS (WESTONIA) sp. undt.
A fragment of shell suggesting the outline of O. (W.) finlandensis
Walcott * preserves the outer surface with the characteristic irre-
* Amer. Jour. Sci., 5th Ser., Vol. 3, 1922, pp. 343-348.
?Mong. U. S. Geol. Surv., No. 51, 1912, pl. 48, fig. 3.
7 ;

524 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

gular inosculating transverse surface lines of Westonia aurora
(Hall) ," an Upper Cambrian shell.

Formation and locality—Oczarkian: (67y) Russia, Island of
Novaya Zemlya, west coast of southern island, north side of Gribovii
Fjord.

Genus LINGULELLA Salter
LINGULELLA cf. DESIDERATA Walcott
Plate 123, figs. 3-5

This species belongs with a group of small forms that are repre-
sented by Lingulella desiderata Walcott * which has a wide area dis-
tribution and ranges from the Upper Cambrian into the Mons for-
nation of the Ozarkian. The Novaya Zemlya specimens are fairly
well preserved and appear to be within the range of variation of the
western North American species.

Formation and locality—Ozarkian: (68b) Russia; Island of
Novaya Zemlya; west coast of southern island; Mountains 7 km.
northwest of the head of Bessimyanni Fjord.

LINGULELLA ARCTICA, new species
Plate 123, figs. 1, 2

This species agrees in size and outline with the various forms of
Lingulella bella Walcott, except that it is more elongate. There are
only two specimens of the dorsal valve. The shell is largely exfoliated
and on the cast of the interior the lines of advance of the central and
anterior lateral muscle scars and median septum are outlined; the
anterior lateral muscle scars extended into the anterior third of the
valve. Fragments of the shell show it to have been of medium thick-
ness and marked on the outer surface by fine concentric lines and
strie of growth.

A valve somewhat flattened by compression is 13 mm. in length
and has a maximum width of 6.5 mm.

There is no closely related species to L. arctica in the Upper Cam-
brian or in the Mons formation of the Lower Ozarkian. Some of
the smaller species from the latter formation are elongate, notably
L, ibicus,’ but they are quite distinct in outline of the valves.

Formation and locality—lLower Ozarkian: (67y) Russia; Island
of Novaya Zemlya, west coast of southern island; Gribovii Fjord.

SLO GHCIL plerAOwsT hy

* Mong. U. S. Geol. Sufv., No. 51, 1912, pl. 51, figs. 4 and 5.

* Mong. U. S. Geol. Surv., No. 51, 1912, p. 481, pl. 19, figs. 2d-f.
*Smithsonian Misc. Coll., Vol. 67, No. 9, 1924, pl. 108, figs. 5-8.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 525

Genus ACROTRETA KUTORGA
ACROTRETA, sp. undt.

A very small species of Acrotreta is represented by several dorsal
valves and crushed ventral valves from which the shell has been
exfoliated. The cast of the interior of the dorsal valve shows a long,
strong median septum such as occurs in both Middle and Upper Cam-
brian species, also the Mons formation of the Lower Ozarkian, which
has two species A. atticus Walcott and A. discoidea Walcott. The
dorsal valve of A. atticus is very much like that of the Novaya
Zemlya species. The dorsal valves vary from 2 to 3 mm. in diameter.

Formation and locality—Ozarkian: (67y) Russia, Island of
Novaya Zemlya, west coast of southern island, north side of Gribovii
Fjord, and (68b) Mountains 7 km. northwest of the head of Bessi-
myanni Fjord.

Genus BILLINGSELLA Hall and Clarke
BILLINGSELLA HOLTEDAHLI, new species
Plate 123, figs. 6-16

Dr. Holtedahl calls attention to a shell ‘‘ that may be nearly related
to Billingsella coloradoensis* that is quite abundant. I find that
while the species resembles B. coloradoensis (Shumard) closely, it
differs in its larger size, outline of cardinal angles, and more uniform
surface plications.

Some of the smaller shells may belong to another species, but with
the material available it seems best to retain them with the larger
shells. The surface characters vary owing to the varying amount
of exfoliation caused by adhering to the matrix. It is exceptional
to find a specimen with the outer surface uninjured.

Formation and locality—Ozarkian: (67y) Russia, Island of
Novaya Zemlya, west coast of southern island, Gribovii Fjord.

BILLINGSELLA ? OPPIUS, new species
Plate 124, figs. 1-8

This species is characterized by the transverse outline of ihe valve
and uniform rather coarse plications which increase in number by
intercalation from near the beak towards the front of the valves.
The transverse outline and plication of the valves is more like that of
Protorthis billingsi (Hartt)* than either Billingsella or Eoorthis,

* Amer. Jour. Sci., 5th Ser., Vol. 3, 1922, p. 345.
*Mong. U. S. Geol. Surv., No. 51, 1912, pl. 90, figs. 1, 1a-f.

526 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Formation and locality—Ozarkian: (67y) Russia, Island of
Novaya Zemlya, west coast of southern island, north side of Gribovit
Fjord.

Genus EOORTHIS Walcott
Eoorthis Walcott, Mong. U. S. Geol. Surv., No. 51, 1912, p. 772.

EOORTHIS SABUS, new species
Plate 124, figs. 9-15

This species recalls, as Dr. Holtedahl mentions, Eoorthis wichi-
taensis (Walcott). It differs from it in its stronger higher umbo and
more abrupt cardinal slopes on the ventral valve. The surface plica-
tions and elevated radiating lines vary considerably.

Formation and locality—Ozarkian: (68b) Russia, Island of
Novaya Zemlya, west coast of southern island, mountains 7 km.
northwest of the head cf Bessimyanni Fjord.

Genus HUENELLA Walcott
See Mong. U. S. Geol. Surv., Vol. 51, 1912, p. 805.

HUENELLA TRIPLICATA, new species
Plate 125, figs. I-15

Huenella cf. texana Holtedahl, 1922, Amer. Jour. Sci., 5th Ser., Vol. III,
p. 345, fig. 1. (Illustrates dorsal and ventral valves and compares them
with H. texana Walcott.)

This species differs from H. texana, its nearest representative, in
the more uniform distribution of narrow plications on the cardinal
slopes, the presence of one or two narrow plications in the strong
mesial sinus of the ventral valve, and three strong narrow plications
on the high median fold of the dorsal valve.

The cast of the spondilium of the ventral valve is finely pre-
served in a number of specimens but the main vascular sinuses are
somewhat indistinct. The cast of the interior of the dorsal valve
shows a small shallow spondilium, anterior and posterior adductor
muscle impressions; a rather low area and open delthyrium is pre-
served on a ventral valve.

The discovery of the genus Huenella in Novaya Zemlya by Holte-
dahl is most interesting, as it is there associated with a lower Ozarkian
fauna. In western North America the genus occurs in both the
Upper Cambrian and Lower Ozarkian. The species from the latter
are H. orientalis Walcott, H. texana Walcott, and var. laeviuscula.
H., icetas Walcott, and H. juba Walcott.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 527

Formation and locality—Ozarkian: (68b) Russia, Island of
Novaya Zemlya, west coast of southern island, mountains 7 km.
northwest of the head of Bessimyanni Fjord.

CEPHALOPODA

I have not met with any cephalopods in the Cambrian formations
of America. They first appear in the Hungaia zone of the super-
jacent Lower Ozarkian of the Mt. Robson section and higher up in
the upper part of the Mons formation which corresponds in a
general way with Etage 3ay of Brogger’s section.’ He illustrates two
species, Orthoceras attavus, plate 4, figure 9, by a fragment of a
phragmacone of a small conch, and Orthoceras n. sp. (pl. 4, figs. 8
and 10) by fragments of a larger conch preserving a portion of the
living chamber and the phragmacone. Both of these species may
fall in the genus Ellesmeroceras Foerste.

The range of variation among the specimens of Ellesmeroceras
robsonensis from the Chushina formation in the Robson district
appears to include the specimens referred to the latter species that
occur in association with a different grouping of genera and species
which may be several hundred feet higher in the section of the Mons
formation in the Glacier Lake district. It is possible that the cephalo-
pods came from the Arctic province and did not reach the Glacier
Lake district until long after appearing in the Robson district. In
any event their presence with the Hungaia fauna in association with
Symphysurina indicates a somewhat older fauna than that of the
Upper Mons to the southeast.

The identity of Endoceras (?) monsensis of the Upper Mons fauna
in the Hungaia fauna of the Robson district is more uncertain than
that of Ellesmeroceras robsonensis, but it is a similar form and
strengthens the view that the Hungaia fauna of the Chushina forma-
tion of the Robson district is allied to that of the Upper Mons.

Genus ELLESMEROCERAS Foerste

See Davidson University Bull., Vol. 19, 1921, p. 265. (Description and
illustration of type species E. scheii.)

ELLESMEROCERAS ROBSONENSIS, new species
Plate 126, figs. 5-9a
Conch straight on both the ventral and dorsal sides. Apical angle
8° as viewed from the ventral side. Conch sometimes compressed

* Die Silurischen Etagen 2 und 3, 1882, pp. 30-177.

528 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

laterally so as to give a slightly oval transverse section but in most
specimens the section is circular. Shell thin and readily broken. No
trace of surface ornamentation has been observed. |

A round conch 6.5 mm. in diameter at the base of the living chamber
has five camerze of almost equal length on a distance of 5 mm. from
the living chamber. Ina specimen 4 mm. in transverse diameter there
are 5 camer in a distance of 4 mm., and another 5.25 mm.in diameter
at the apical end has 16 camere in a distance of 18 mm. The sutures
of the septa slope from the siphuncle along the median line of the
ventral side downward and arch slightly backward at the sides and
then forward so as to be slightly in advance of their position on the
ventral side where they meet the median line on the dorsal side. On
some specimens the sutures are almost at right angles to the axis
of the conch.

The siphuncle is small, round and oval in compressed conchs; it is
in contact with the ventral wall of the conch; in a compressed septum
6 mm. in its dorso-ventral diameter the siphuncle has a dorso-ventral
diameter of 2.25 mm. by 1.75 mm. The septa are rather strongly
concave so that their depth is equal to the space between the sutures.
The siphuncle contracts a little between the septa, which gives it a
slightly beaded appearance.

The outer chamber of the conch is not fully preserved, but one
specimen indicates that it was slightly expanded towards the upper
end.

Observations.—This is a small species of which many fragments
are found in association with brachiopods and fragments of trilobites.
The largest living chamber in the collection has a diameter of 8 mm.
a little in advance of the last camerz which indicates that the conch
was not over 6 to 6.5 cm. in length.

This conch seems to fall within the genus Ellesmeroceras as de-
scribed and illustrated by Foerste. The exact stratigraphic horizon
of the type species is in doubt, but as the closely allied form E. rob-
sonensis is from the Lower Ozarkian, it may be that the genotype is
from the Lower Ozarkian, as it is a.straight conch and not curved as
are most of the Upper Ozarkian conches in which the siphuncle is in
contact with the ventral wall. E. schei Foerste is from Ellesmereland
and is tentatively referred to the Canadian (Ordovician) by Foerste.

Formation and locality—lLower Ozarkian: (61q) Chushina for-
mation. Gray limestone in beds of varying thickness, one or two
layers quite ferruginous. In Billings Butte (Extinguisher) at end of
west spur of Mount Lynx, above Hunga Glacier and east of Robson

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 529

Peak, Robson Park, northwest of Yellowhead Pass, in eastern British
Columbia, Canada.

Mons formation: (64p) Cliff on southeast side of Mons Glacier,
above head of Glacier Lake canyon valley, about 50 miles (80.4 km.)
northwest of Lake Louise Station on the Canadian Pacific Railway,
Alberta, Canada.

Mons formation: (65z) ta of section. North side of Clearwater
Canyon, 2 miles (3.2 km.) from divide at head of canyon and about
21 miles (33.6 km.) in an air'line north, 2° west, of Lake Louise
Station on the Canadian Pacific Railway, Alberta, Canada.

Ozarkian: (66n) Mons formation. Thin-bedded gray limestone,1a
of section, 255 feet (77.7 m.) from summit of Mons. 8.7 miles (13.9
km.) northeast in air line of Lake Louise Station on the Canadian
Pacific. Railway at the east foot of Fossil Mountain, Alberta, Canada.

A fragment of a somewhat similar form of conch that may belong
to Ellesmeroceras occurs at locality 30w. Lower Ozarkian: Notch
Peak formation. Drift boulder supposed to have been derived from ta
of section. About 2 miles (3.2 km.) south of Marjum Pass, House
Range, Millard County, Utah.

ENDOCERAS (?) MONSENSIS, new species
Plate 126, figs. 4, 4a, 4b

Conch annulated, straight, laterally compressed so as to give an
oval dorso-ventral section. A septum with a major axis of 3.75 mm.
has a transverse axis of 2.75 mm.; this specimen of the phragmacone
has 5 strong narrow annulations in a distance of 8 mm., with rounded
depressions between. No trace of surface ornamentation has been
observed. Living chamber and siphuncle unknown.

A specimen 9 mm. in length has 5 camere of almost equal length:
the sutures of the septa cross the ventral side at the foot of the lower
(apical) slope of the annular ridge and slope backward so as to cross
the front slope of the next posterior annular ridge midway between
the ventral and dorsal median axial line and then curve forward to
meet at the dorsai median axial line on the back slope of the annular
ridge directly opposite the suture on the ventral side. Septa concave
and nearly as deep as the length of the camerz.

A portion of a phragmacone occurs with the Lower Ozarkian
fauna at locality 185z that is similar to that of E. (?) monsensis
except that the annular ridges are not as prominent, but as this may
result from the condition of preservation, I am tentatively referring
the specimen to this species.

530 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

Observations—The largest conch in the collection has a dorso-ven-
tral diameter of 3.75 mm. The outer shell of the conch was thin and
readily crushed so as to throw the septa at a very oblique angle to the
axis. Specimens are rarely seen even as fragments.

In the absence of surface markings, siphuncle and living chamber, I
refer the species to Endoceras, pending the discovery of more com-
plete specimens. It has some of the characters of Ellesmeroceras but
the strong annulations may indicate other differences that may be of
generic importance.

Formation and locality —Lower Ozarkian: (64p) Mons formation,
18 feet (5.4 m.) from top of 1a of field section. Cliff on southeast
side of Mons Glacier, above head of Glacier Lake Canyon Valley,
about 50 miles (80.4 km.) northwest of Lake Louise Station on
Canadian Pacific Railway. (66n) Thin-bedded gray limestone, 1a of
section, 255 feet (77.7 m.) from summit of Mons. 8.7 miles (13.9
km.) northeast in air line of Lake Louise Station on the Canadian
Pacific Railway at the east foot of Fossil Mountain, Alberta, Canada.

(61q) Chushina formation: gray limestone in beds of varying
thickness, one or two layers quite ferruginous. In Billings Butte (Ex-
tinguisher) at end of west spur of Mount Lynx, above Hunga Glacier
and east of Robson Peak, Robson Park, northwest of Yellowhead
Pass, in eastern British Columbia, Canada.

The specimens from the Chushina formation are very small and
slender and may possibly belong to another species.

Lower Ozarkian: (185z) St. Charles formation. Blacksmith Fork
Canyon about 9 miles (14.4 km.) east of Hyrum, Cache County,
Utah.

NOTOSTRACA SARS
Family TECHNOPHORIDZ Miller

Technophoride Miller, 1889, North Amer. Geol. and Pal., p. 458.

S. A. Miller proposed this term to include the genus Technophorus,
and referred one species to it, T. faberi Miller. He considered the
species to be a lamellibranch, where it remained until 1913 when
Dr. R. S. Bassler placed Technophorus along with Euchasma, Eop-
teria and Ischyrina Billings under the Branchiopoda and order
Notostraca, as he considered that the carapace was folded over on the

* Text Book pal. Zittle, Eastman, 1913, p. 733.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 531

median ventral line as in Apus and that there was not any hinge line
present.

All of the genera of the Technophoride have the dorsal shield
folded sharply over the ventral median line so as to form a bivalve
appearing shell that was considered to be that of a lamellibranch ; this
deception was accentuated by the interior of the carapace, which has
on each side a ridge extending down from near the ventral median
line more or less obliquely towards the margin of the carapace, and the
casts of the interior showed also a strong beak projecting anteriorly.
It was quite natural to compare the supposed lamellibranch with
Nuculites and to refer it to the family Ctenodontide.

All of the genera mentioned have a strong rib or ribs extending
from the highest point on the antero-ventral fold to the postero-
lateral angle of the carapace, that gives them a very distinct character
that is unlike that of the genus Ozomia now proposed for the species
occurring in the Lower Ozarkian.

Genus OZOMIA, new genus

Carapace as folded on the median ventral line, equivalue, inequi-
lateral, transverse ; rounded subquadrilateral in outline on each side;
moderately convex on each side; the margins of the carapace met
beneath the dorsal side and gapped a little at the anterior and poster-
ior ends; outer surface smooth. Interior of carapace on each side
with a short clavicular-like ridge; adductor muscle scar between the
ridge and anterior margin of the carapace.

Genotype —Ozomia lucan Walcott.

Stratigraphic range-——Upper 50 feet (15.2 m.) of the Lower
Ozarkian Mons formation.

Geographic distribution.—Cordilleran area from Glacier Lake near
the bead of the Saskatchewan River, Alberta, Canada, southeast
49 miles (78.8 km.) to Fossil Mountain and head of Douglas Lake
Canyon north of Bonnett Peak ; also about 800 miles (1287 km.) south
in Blacksmith Fork canyon in northern Utah.

OZOMIA LUCAN, new species
Plate 120) fies) Is 2) 3hce
This species is known only from natural casts of the interior of the
two sides of the carapace; the casts indicate a moderate convexity ; a
rounded outline with a straight ventral margin from the high point out

532 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

to the broadly rounded posterior ends; in some specimens the poster-
ior fourth of the margin slopes upward and the anterior end is almost
as broadly rounded as the posterior. The length of the carapace is a
little greater than the distance from the median ventral fold to the
margins. The largest undistorted specimen in the collection has a
height of 9.25 mm. on each side and length of 11.5 mm. The sides
gaped slightly at both the anterior and posterior ends, as indicated
by the casts. The test was thin on the sides and in all localities and
condition of preservation in the different layers of limestone it adheres
to the matrix so closely that no traces have been observed of its outer
surface ; it was probably smooth or finely lined as the casts show only
a faint trace of lines radiating from the anterior crest of the fold
toward the postero-lateral margins.

The cast. of the interior indicates a narrow deep clavicular-like
ridge that extends about one-fourth the distance towards the antero-
basal margin, or it may be directed towards the postero-basal margin ;
the two extremes of direction are illustrated by figures I, 2, 3, pl. 121.

A rather large adductor muscle scar is faintly outlined between the
clavicular-like ridge and the anterior margin.

Observations.—This is the only species of the genus known to me.

The type specimens of O. lucan are from the upper portion of the
Mons formation, locality 66n. The species is also known from the
Glacier Lake—Saskatchewan River area and southeast to the north-
ern section of the Sawback Range, Alberta, and in the Blacksmith
Fork section of northern Utah.

Formation and locality:—Ozarkian: (66n) Mons formation. Thin-
bedded gray limestone, Ia of section, 255 feet (77.7 m.) from summit
of Mons. 8.7 miles (13.9 km.) northeast in air line of Lake Louise
Station on the Canadian Pacific Railway at the east foot of Fossil
Mountain. (64p) 18 feet (5.4 m.) from top of 1a of field section.
Cliff on southeast side of Mons glacier, above head of Glacier Lake
Canyon Valley, about 50 miles (80.4 km.) northwest of Lake Louise
Station on the Canadian Pacific Railway, Alberta, Canada. (65g)
Block that fell from cliff above southeast Lyell Glacier, about 50
miles (80.4 km.) northwest of Lake Louise Station on the Canadian
Pacific Railway. (65z) 1a of section. North side of Clearwater
Canyon, 2 miles (3.2 km.) from divide at head of canyon and about
21 miles (33.6 km.) in an air line north, 2° west, of Lake Louise
Station on the Canadian Pacific Railway. (67r) Gray limestone in
upper portion of Mons 16 feet (4.8 m.) from top of formation.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 533

Southeast side of head of Douglas Lake Canyon Valley, 12.75 miles
(20.5 km.) east, 5° north, of Lake Louise Station on the Canadian
Pacific Railway, Alberta, Canada.

(185z) St. Charles formation, in limestones about 200 feet (60.9
m.) below No. 1 of section of 1912. Blacksmith Fork Canyon about
g miles (14.4 km.) east of Hyrum, Cache County, Utah.

534 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 106

Micromitra zenobia Walcott
Fic. 1. (X2.) Ventral and dorsal valve, flattened, broken and a little distorted on
the surface of shaly limestone. U. S. Nat. Mus., Cat. No. 69631.
2. (X2.) A ventral and dorsal valve compressed, broken and transversely
distorted on surface of shaly limestone. U. S. Nat. Mus., Cat. No. 69632.
3. (X2.) A small ventral and dorsal valve illustrating transverse distortion.
U. S. Nat. Mus., Cat. No. 69633.
4. (X3.) A ventral and dorsal valve vertically distorted. U. S. Nat. Mus.,
Cat. No. 609634.
5. (Natural size.) A distorted dorsal valve preserving concentric surface
strie. Ul. S. Nat. Mus., Cat. No. 69635.
6. (Natural size.) A dorsal valve shortened by distortion. U. S. Nat. Mus.,
Cat. No. 69636.
(Natural size.) A distorted ventral valve that has the outline of a dorsal
valve of Lingulella. U. S. Nat. Mus., Cat. No. 69637.

The specimens represented by figs. 1-7 are from locality 61j, Middle Cambrian:
Stephen formation; buff weathering band of calcareo-argillaceous shale; west
slope of Mt. Field, B. C., Can.

Obolus ion Walcott

Fic. 8. (X4.) A less acuminate ventral valve than fig. 9. U. S. Nat. Mus., Cat.
No. 69638
9. (X4.) A broad form of ventral valve. U. S. Nat. Mus., Cat. No.
606390.
to. (X4.) A partially exfoliated dorsal valve. U. S. Nat. Mus., Cat. No.
69640.
The specimens represented by figs. 8-10 are from locality 16q, Ozarkian: Mons
formation; thin-bedded gray limestone; Brisco Range, Sinclair Canyon, B. C.,
Can.
Obolus perone. Walcott’ .anre s..cive eng boars hls oles ek eee EE Oe 484
Fic. 11. (X2z2.) Flattened and partially eroded dorsal valve. U. S. Nat. Mus.,
Cat. No. 69641.
The specimen represented by fig. 11 is from the Upper Cambrian: Ottertail
limestone, Moose Creek, southeast of Field, B. C., Can.
Obvolus: leda Woaleott:.)s,5, .sr5,stis <(ra cracofory sistarere sist ois oto ae hotles ete ICTR eee 483
Fic. 12. (X6.) A ventral valve doubtfully referred to this species. U. S. Nat.
Mus., Cat. No. 69642.
13. (X6.) Ventral valve. The front margin outlined from fig. 14. U. S. Nat.
Mus., Cat. No. 69643.
14. (X6.) Interior of ventral valve. U. S. Nat. Mus., Cat. No. 69644.
15. (X6.) Exterior of dorsal valve. U. S. Nat. Mus., Cat. No. 69645.
The specimens represented by figs. 12-15 are from locality 30m, Ozarkian:
Notch Peak formation; compact dove-colored limestone, north slope of Notch
Peak, House Range, Utah.
Micromitra (Iphidella) pannula (White) ...........ceecceccevccecccccvcceecevesces 481

Fic. 16. (X3.) A ventral valve with fine sete beautifully preserved. U. S. Nat.
Mus., Cat. No. 69646.
17. (X3.) Ventral valve preserving Reais and sete. U. S. Nat. Mus., Cat.
No. 59801.

This specimen was illustrated in 1913, Research in China, Vol. 3, Cambrian
Faunas of China, pl. 1, fig. 13.

The two specimens represented by figs. 16 and 17 are from locality 35k, Middle
Cambrian: Burgess Shale, north of Field, B. C., Can.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9, PL. 106

MICROMITRA-OBOLUS.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 95) PE. 107,

OBOLUS.

NO. Q CAMBRIAN AND OZARKIAN BRACHIOPODA 535

DESCRIPTION OF PLATE 107

reed Mp MENTS BE WN ANON 3 2) 5s carck sroips x cvlave eaux ake wile Shot din Myeaicatts ae Sy ob ahaa) dincaial As 484
Fic. 1. (X 6.) Interior of a ventral valve flattened in shaly limestone

so as to give it too much width. U. S. Nat. Mus., Cat. No.
60647.

2. (xX 6.) Dorsal valve associated with the ventral valve fig. 1,
widened by compression. U.S. Nat. Mus., Cat. No. 60648.

3. (X< 6.) Exfoliated dorsal valve in limestone preserving the
natural outline. U. S. Nat. Mus., Cat. No. 69649.

The specimens represented by figs. 1-3 are from locality 63x, Upper
Cambrian: Ottertail formation; thin-bedded limestone, Wolverine
Passes. @an:

KO a REN MELOLO TCIUSUSS NVi2ll COLD ayo) ajsvote oi ches eto c esc nine 6 ikl soe ee al ores ar ciioiers Sind a e's 484
Fic. 4. (X.4.) Partially exfoliated dorsal valve. U. S. Nat. Mus., Cat.
No. 69650.

5. (X4.) Exfoliated ventral valve with front margin broken. U.S.
Nat. Mus., Cat. No. 69651.

The specimens represented by figs. 4 and 5 are from locality 61q,
Ozarkian: Chushina formation, gray limestone, Robson Peak Dis-
ince b:, C.,;. Can.

Obates. Fegan SMC eB Ab GoGo 65 Sul oc Obed ORD RD Ohnn os One cmon anne 486
Fic. 6. (X 4.) Partially exfoliated ventral valve. U. S. Nat. Mus., Cat.
No. 609652.

The specimen represented by fig. 6 is from locality 16r, Ozarkian:
Mons formation; Brisco Range, Sinclair Canyon, B. C., Can.

Micmiamricesronsa,) ferisa VW alCOtbs se: fe ca ects os cade scene ene sa eeees 487
Fics. 7, 7a. (X4.) Exterior view of ventral valve and side outline
showing convexity. U. S. Nat. Mus., Cat. No. 60653.
8. (xX 4.) Dorsal valve associated with specimen represented by
fig. 7, U. S. Nat. Mus., Cat. No. 69654.

The specimens represented by figs. 7, 7a, 8, are from locality 67n,
Ordovician: Sarbach formation, in a hard, dirty gray, limestone,
northeast slope of Fossil Mountain, Alberta, Can.

530 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 108

Obolus (Fordinta) nestor, Walcott.) 1. . > sym ces eesians onto nee ities ae eee 488
Fic. 1. (X4.) Partially exfoliated dorsal valve in which the visceral area is out-
lined. U. S. Nat. Mus., Cat. No. 69655.
2. (X6.) A small ventral valve associated with the specimen represented by
fig. 1. U. S. Nat. Mus., Cat. No. 69656.

The specimens represented by figs. 1 and 2 are from locality 64w, Upper Cam-
brian: Lyell formation, Sawback Range, Alberta, Can.

Lingulelia (ck destderata: NValcotticrevel- ape set eucjere) eveloieyelere ereicle @ elelohane tee ntaete one ee 490
fee an Oe Ventral valve with fine concentric strie. U. S. Nat. Mus., Cat.
0. 69657.

4. (X6.) A small convex dorsal valve. U. S. Nat. Mus., Cat. No. 69658.

The specimens represented by figs. 3 and 4 are from locality 61q, Ozarkian:
Chushina formation; gray limestone, Robson Peak, B. C., Can.

Lingulellatibicus Walcotts ((See/pl., 109; figs: .8; 0) o-s eneee secon oem iee ate 491
Fic. 5. (X6.) A finely preserved ventral valve. U. S. Nat. Mus., Cat. No. 696509.
Gr ORG) US: Nats Mitise Gata Now ioostz.
7. (X4.) A dorsal valve varying slightly in outline from fig. 8. U. S. Nat.
Mus., Cat. No. 69661.
8. (X4.) <A dorsal valve associated with the specimen represented by fig. s.
U. S. Nat. Mus., Cat. No. 69662.

The specimens represented by figs. 5-8 are from locality 61q. Same as for
figures 3, 4 above.

Lingulella nepos Walcott........ Fefsis\aVaslle(s/e wtn\e\ eta e/a) ate (alee (eletele/a)e ot clalats|oletal te iete ieee ane 493
Fic. 9. (X6.) Partially exfoliated ventral valve. U. S. Nat. Mus., Cat. No.
69663.

to. (X6.) Well preserved dorsal valve. U. S. Nat. Mus., Cat. No. 69664.
Ir. (X6.) A small ventral valve preserving the outer surface of the test.
U. S. Nat. Mus., Cat. No. 69665.

The specimens represented by figs. 9-11 are from locality 16q, Ozarkian:
Mons formation, in thin-bedded gray limestone; Brisco Range, Sinclair Canyon,
Be Ce Cant

Lingulella: “nechias, Walcott o..oi:--. «cies sicieiea’alars vie. 0 veie ocho oo ayeleye.enein oletonstalerae tee eee 492
Fics. 12, 12a. (X2.) Top view and side outline of a dorsal valve. U. S. Nat. Mus.,
Cat. No. 69666.

The specimens represented by figs. 12, 12a, are from locality 67n, Ordovician:
Sarbach formation, in a hard, dirty gray, limestone. Northeast slope of Fossil
Mountain, Alberta, Can.

Lingulella: mera: Wraleotte) soi. 5c cis tyatis hexeve alo shonin ten ORT Oe eee 5a
Fics. 13, 13a. (X4.) Top view and side outline of ventral valve. U. S. Nat. Mus.,
Cat. No. 69667. E
14. (X4.) Top view of dorsal valve. U. S. Nat. Mus., Cat. No. 69668.

The specimens represented by figs. 13 and 14 are from locality 16r, Ozarkian:
Mons formation; Brisco Range, Sinclair Canyon, B. C., Can.

493

Enngulellasnimius EN alcottsacicseim cae cis se.cio cere aoe teieiiie eietetens Banot odopono DAS asta, AOL
Fic. 15. (X6.) Ventral valve preserving a little of the exterior surface. U. S.
Nat. Mus., Cat. No. 69669.
16. (X4.) Partially exfoliated dorsal valve. U. S. Nat. Mus., Cat. No. 69670.

The specimens represented by figs. 15 and 16 are from locality 61q, as given
under figs. 3 and 4 above.
Lingulella siliqua Walcott. (See pl. 100, fig. 1).-.--.2.sseceeesseeseeesreees css een 405
Fic. 17. (X4.) A ventral ? valve partially flattened on the surface of shaly lime-

stone. U. S. Nat. Mus., Cat. No. 69671. P

18. (X4.) A small imperfect ventral valve broken out of limestone. U. S.
Nat. Mus., Cat. No. 69672. :

19. (X4.) A crushed and somewhat broken dorsal valve on surface of lime-
stone. U. S. Nat. Mus., Cat. No. 69673.

The specimens represented by figs. 17-19 are from locality 63x, Upper Cam-
brian: Ottertail formation; thin-bedded limestones, Wolverine Pass, B. C., Can.

VOES G71 NOs oO, FL. 108

SMITHSONIAN MISCELLANEOUS COLLECTIONS

LINGULELLA.

OBOLUS

VOL. 67, NO. 9, PL. 109

SMITHSONIAN MISCELLANEOUS COLLECTIONS

NISUSIA.

ACROTRETA

-LINGULEPIS-

LINGULELLA

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 537

DESCRIPTION OF PLATE 109

Psnoulella siltqua Walcott. (See pli 108, figs: 17-10). <0 oceccccssebcctdcs colmeeccns 495
Fic. 1. (X4.) A crushed dorsal valve doubtfully referred to this species. U. S.
Nat. Mus., Cat. No. 69674.

For locality, see pl. 108, figs. 17-10.

HEMP TAELELMEROMUUSEANN ICO LL ine a is ei cte stoke a cravsin Cieienale sl Seles chee Ghia ela Nomad & oman Se aomsee 494
Fics. 2, 2a. (X4). Ventral valve and side outline. U. S. Nat. Mus., Cat. No.
60675.

3. (X4.) Dorsal valve and side outline. U. S. Nat. Mus., Cat. No. 60676.

The specimens represented by figs. 2, 2a, 3 are from locality 61q, Ozarkian;
Chushina formation; gray limestone, Robson Peak District, B. C., Can.

LVS EIROS: CATIEOEN DIES ro paid BO Or ae GOGO CCUG GHOSE E RO ner Or ar coGnc Detiicris or 489
Fic. 4. (X6.) A small but well preserved ventral valve. U. S. Nat. Mus., Cat.
No. 69677.

5. (X6.) Acuminate ventral valve with front margin broken away. U. S.. Nat.
Mus., Cat. No. 69678.

6. (X6.) A broad ventral valve that may not belong to this species. U. S.
Nat. Mus., Cat. No. 69679.

7. (X6.) Partially exfoliated dorsal valve illustrating vascular markings.
U. S. Nat. Mus., Cat. No. 69680.

The specimens represented by figs. 4-7 are from locality 16q, Ozarkian: Mons
formation, gray limestone; Brisco Range, Sinclair Canyon, B. C., Can.

Lingulella ibicus Walcott. (See pl. 108, figs. 5-8)..--... eee eee ree eee ee eet te eee ees 491
Fic. 8. (X6.) <A ventral valve from the type locality 61q. (See description of
figs. 5-8, pl. 108.) U.S. Nat. Mus., Cat. No. 69660.
9. (X6.) A dorsal valve from Sinclair Canyon, locality 16q. (See under
description of fig. 7 above). U. S. Nat. Mus., Cat. No. 69681.

ee EC LMA TLELSCAES MANA COLE ee Ties oe cae oat ei Sisto e ® Saldin ielwte: aiSiars, sis el srpleisio tes 496
Fic. 10, 10a. (X6.) Top, side and back view of a ventral valve. U.S. Nat. Mus.,
Cat. No. 61682.
11, 11a. (X6.) Top, side and back view of a ventral valve. U. S. Nat. Mus.,
Cat. No. 61683.
12. (X6.) Natural cast of interior of dorsal valve. U. S. Nat. Mus., Cat.
No. 61684.

The specimens represented by figs. 10-12 are from locality 61q. (See fig. 2,
above.)

PAP AEREL Lue LUSGOTULCIL ENV al COLtarataieie ole are ferel aioe ele ecoveterc leyelo! sys are elena = eiche siew old efestel cle\(e sila e/s tele 497
Fic. 13. (X6.) Top view of ventral valve. U. S. Nat. Mus., Cat. No. 69685.
14. (X6.) Exterior of dorsal valve. U. S. Nat. Mus., 69686.

The specimens represented by figs. 13 and 14 are from locality 61q (see fig. 2,
above).

INSSHESUD MES PINIG CTU NViAICOtE >. c:c1c 0/e stare, ©] elere aterots'a ol cle. eis)s ya lefsisls = ierasis\s/0le/el s\,selevereiaic sane ex o's 498
Fic. 15. (X4.) Exterior of a dorsal valve. U. S. Nat. Mus., Cat. No. 69687.
16. (X6.) Spines on surface coste. U. S. Nat. Mus., Cat. No. 69688.
17. (X4.) Interior of a ventral valve. U. S. Nat. Mus., Cat. No. 69689.
The specimens represented by figs. 15-17 are from locality 63x, Upper Cam-
brian: Ottertail formation; limestones, Wolverine Pass, B. C., Can.

538 SMITHSONIAN MISCELLANEOUS COLLECTIONS ~— VOL. 67
DESCRIPTION OF PLATE 110
PAGE
Nisusta burgessensts: WaleOtt. 125) 5 os00%! soe inte oo oa ee ee 499
Fic. 1. (X 3.) Ventral valve with attached surface spines. U. S. Nat.
Mus., Cat. No. 69690.
- 2. (X2.) Natural cast of exterior of a compressed ventral valve.
U. S. Nat. Mus., Cat. No. 69691.
3. (X2.) Interior of a dorsal valve. U. S. Nat. Mus., Cat. No.
69602.
4. (X2.) Outer surface of shell. U. S. Nat. Mus., Cat. No. 69693.
5. (X<6.) A small ventral valve enlarged to illustrate outer sur-
face. U. S. Nat. Mus., Cat. No. 69694.
6. (X2.) Interior of a ventral valve. U. S. Nat. Mus., Cat. No.
60605.
7. .(X2.) Exterior of a dorsal valve. U. S. Nat. Mus., Gat Na:
69606. :
8. (X2.) Top view of natural cast of interior of a dorsal valve.

U. S. Nat. Mus., Cat. No. 69697.

The specimens represented by figs. 1-8 are from locality 35k,
Middle Cambrian: Burgess shale, B. C., Can.

Nisusia ((Samesella), orsens: INValcotts. oe. a- hose ae eee Cee

Fic. 9,
10,
II,
12,
13,

14,

oa. (X2.) Top and side views of a ventral valve with pro-
longed mesial sinus. U. S. Nat. Mus., Cat. No. 69608.

tod. (X2.) Top and side views of a ventral valve with a broad
mesial sinus. U. S. Nat. Mus., Cat. No. 69699.

500

Ila. (X2.) Ventral valve with a small dorsal valve beside it.

U.S. Nat. Mus., Cat. No. 69700.

12a. (X2.) Top and side view of a ventral valve. U. S. Nat.

Mus., Cat. No. 69701.

13a. (X2.) Top and side view of a dorsal valve. U. S. Nat.
Mus., Cat. No. 69702. ~

14a. (X2.) Top and side view of a depressed dorsal valve.
U. S. Nat. Mus., Cat. No. 69703.

The specimens represented by figs. 9-14a are from locality 41b,
Lower Cambrian: lower beds of Forteau Point, Forteau Bay, north
shore of Straits of Belle Isle, Labrador, Canada.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOE G7 NO. o,eeE. 110

NISUSIA.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9; PE. 411

NISUSIA~-WIMANELLA-BILLINGSELLA-PROTORTHIS.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 539
DESCRIPTION OF PLATE 111
PAGE
Denethn THERIAN CRITI ICH UC a cisraie sistcis xie's « % ease. dg emt Roce ase ehdaibiers,6 clouds Ciole ae aieas 499
Pres. 1.10. (x 2:) Top and side view. U. S. Nat. Mus., Cat: No.
69704. ;

The specimens represented by figs. 1 and 1a are from locality 14s,
Middle Cambrian: Stephen formation; Mount Stephen, above Field,
BeG. Carn:

WEL IE CAO RELL USEMN Viel COL Uepepeten cuts « cis sve’ s: distarele «’siclotens aise eke GAS ¢ wlare seme a oles
Fic. 2. (X 4.) Portion of an exfoliated ventral valve with faint vas-
cular sinuses. U. S. Nat. Mus., Cat. No. 69705.
3. (<4.) A-small ventral valve with acute cardinal angles. U. S.
Nat. Mus., Cat. No. 69706.
4. (X4.) Exfoliated dorsal valve with acute cardinal angle.
U. S. Nat. Mus., Cat. No. 69707. >

The specimens represented by figs. 2-4 are from locality 61v, Middle
Cambrian: Titkana formation; gray shaly limestone, Robson Peak
District, Alberta, Can.

Ef ANCHO COLL CH SIN ALCOR stro sisi oie: ciate. o arorctala:s 0 avo’) vtovesd.ale ore. d leks un ehavieleie
Fic. 5. (xX 4.) Natural casts of interior of ventral valves. U. S. Nat.
Mus., Cat. No. 69708.
6. (X<4.) Natural cast of interior of a dorsal valve. U. S. Nat.
Mus., Cat. No. 69700.

7. (X4.) Partially exfoliated dorsal valve somewhat doubtfully
referred to this species. U. S. Nat. Mus., Cat. No. 69710.

The specimens represented by figs. 5-7 are from locality 641, Upper
Cambrian: Lyell formation; gray limestone, Glacier Lake Canyon,
Alberta, Can.

Parte l OW NN ANCE Tch fi tictslecbeteest sched Sic) ines aja ais b> blocs ale oiWec)e cede dalbar
Fic. 8. (x 4.) Exterior of dorsal valve. U. S. Nat. Mus., Cat. No.
69711.

9. (xX 4.) Partially exfoliated ventral valve showing main sinuses.
U.S. Nat. Mus., Cat. No. 69712.

The specimens represented by figs. 8 and 9 are from locality 21j,
Ozarkian: Mons formation, hard gray limestone, east of Golden,
Bean Gane

eR S OPERAS AVY ACO. cha arc eae Wide esa eidisie e's onic s due edb aie tote ew a at
Fics. 10, 10a, 10b. (X 4.) Top, side and back view of a small! ventral
valve. U. S. Nat. Mus., Cat. No. 69713.
Il. (X2.) Partially exfoliated dorsal valve. U. S. Nat. Mus., Cat.
No. 69714.

The specimens represented by figs. 10, 10a, 10b, and 11 are from
locality 65w, Ozarkian: Mons formation, Clearwater Canyon, Al-
berta, Can.

501

502

504

540 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION ‘OF PLATE, 112

Billingsella archias Walcott... 42.5.0:9.c sent oon see eee eee 501
Fic. 1. (> 4.) Exterior of a ventral valve. U. S. Nat. Mus., Cat. No.

69715.

2. (X4.) Natural cast of interior of a ventral valve. U. S. Nat.
Mus., Cat. No. 69716.

3. (x 4.) Natural cast of interior of a broken ventral valve. U. S.
Nat. Mus., Cat. No. 60717.

4. (X<4.) Natural cast of interior of a dorsal valve. U. S> Nat
Mus., Cat. No. 69718.

5. (X4.) Natural cast of an interior of a ventral valve. U. S.
Nat. Mus., Cat. No. 697109.

The specimens represented by figs. 1-5 are from locality 61q, Ozark-
ian: Chushina formation, Robson Peak District, B. C., Can.

Eoorthis oicina, Walcott... osc... 2% « s.0¢ stoeeiee eu tiee ane Hone ee ee 512
Fic. 6. (X 3.) Exterior of ventral valve. U. S. Nat. Mus., Cat. No.
69720.
7. (X3.) Exterior of dorsal valve. U. S. Nat. Mus., Cat. No.
69721.
8 (xX 3.) Exterior of ventral valve. U.S. Nat. Mus., Cat. No..
69722.

9. (xX 3.) Partial cast of interior of ventral valve. U. S. Nat. Mus.,
Cat. No. 69723.

The specimens represented by figs. 6-9 are from locality 65x,
Ozarkian: Mons formation, Clearwater Canyon, Alberta, Can.

VOL. 67, NO. 9;.PE. 1112

SMITHSONIAN MISCELLANEOUS COLLECTIONS

a”
—
md

BILLINGSELLA-EOORTHIS.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO: SPE dina

PROTORTHIS-EOORTHIS.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 541

DESCRIPTION OF PLATE 113

NEMO LOTEMES LOE 1 NV ALGOU Eso tevere ec =e. 2 aia, o)acs «cots mais eras harelercce Seid aipynia o% eater 503
Fic. 1. (X 2.) Partially exfoliated ventral valve. U. S. Nat. Mus.,

Cat. No. 60724.

2. (X2.) Natural cast of interior of a ventral valve. U. S. Nat.
Mus., Cat. No. 69725.

3. (X<2.) Natural cast of interior of a ventral valve. U. S. Nat.
Mus., Cat. No. 69726.

4, 4a, 4b. (X4.) Top, side and back view’ of a small ventral
valve. U. S. Nat. Mus., Cat. No. 69727.

5. (X2.) Partially exfoliated dorsal valve. U. S. Nat. Mus., Cat.
No. 69728.

6. (xX 4.) Outer surface of a dorsal valve. U. S. Nat. Mus., Cat.
No. 69729.

7. (X2.) Partially exfoliated dorsal valve. U. S. Nat. Mus., Cat.
No. 69730.

The specimens represented by figs. 1-7 are from locality 65w,
Ozarkian: Mons formation, Clearwater Canyon, Alberta, Can.

EE UC ICO STCLGENV al COLU mie nie ais ake siercescrs see sie ess ssc ale ses sen 505
Fic. 8. (X 3.) Ventral and dorsal valves on surface of shale. U.S. Nat.

Mus., Cat. No. 69731.

9. (X3.) Natural cast of interior of a ventral valve. U. S. Nat.
Mus., Cat. No. 69732.

10. (xX 3.) Exterior of a compressed ventral valve. U.S. Nat. Mus.,
Cat. No. 69733.

11. (X3.) Interior of a dorsal valve. U. S. Nat. Mus., Cat. No.
69734.

1, (X 3.) Dorsal valve. U.S. Nat. Mus., Cat. No. 60735.

13 and 14. (X3.) Interior of dorsal valves. U. S. Nat. Mus., Cat.
Nos. 69736, 69737.

The specimens represented by figs. 8-14 are from locality 35k,
Middle Cambrian: Burgess shale, above Field, B. C., Can.

542 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 114

EBoorthis 1ophon Walcott (See ple 110; fie. 14) see eeiaee ie eeiee eens
Fic. 1. (X 4.) Small ventral valve. U. S. Nat. Mus., Cat. No. 69738.

2. (X4.) Ventral valve showing outline of visceral cavity be-
neath umbo. U. S. Nat. Mus., Cat. No. 69739.

3. (xX 2.) Dorsal valve with acute cardinal angles. U. S. Nat.
Mus., Cat. No. 69740.

4. (X 2.) Dorsal valve with broad mesial sinus. U. S. Nat. Mus.,
Cat. No. 69741.

5. (xX2.) Exterior of dorsal valve: U. S) Nat; Mus, GateNo:
69742.

The specimens represented by figs. 1-5 are from locality 65e, with
the exception of fig. 3 which is from locality 67w. All are from
Ozarkian: Mons formation, Sawback Range, Alberta, Can.

Foorthis putilius, Walcott (see pl; 115,,fig..0)).. 22 s-0. ieee sees ae ee

Fic. 6. (X 4.) Ventral and dorsal valves in limestone. U. S. Nat. Mus.,
Cat. No. 69743.

7. (<4.) Another group of shells on broken surface of limestone.

U. S. Nat. Mus., Cat. No. 69744. ;

The specimens represented by figs. 6 and 7 are from locality 614,

Ozarkian: Chushina formation; gray limestone, Robson Peak

510

SMITHSONIAN MISCELLANEOUS COLLECTIONS

EOORTHIS

VOL. 67, NO. 9, PL. 115

SMITHSONIAN MISCELLANEOUS COLLECTIONS

EOORTHIS-FINKELNBURGIA.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 543

DESCRIPTION OF PLATE 115

OORENIS: PUlLUS: IGEUIUSCULG. WV aAlCOtts .. ccc ccic co sioe ees vee bss vesiee doe es 5II
Fic: 1. (X<4.) Ventral valves. U. S. Nat. Mus., Cat. No. 60745.
2. (X4.) Dorsal valve associated with specimens shown in fig. I.
U. S. Nat. Mus., Cat. No. 69746.

The specimens represented by figs. 1 and 2 are from locality 67q,
Ozarkian: Mons formation; gray limestone, Douglas Lake Canyon
Valley, Alberta, Can.

LEG ALLOS UTC OROSG: VNEVCEO Eo Heed onan POSOONE con OE OIE coe Creare pee 508
Fics. 3 and 4. (X2.) Casts of exterior of ventral valves. U. S. Nat.
Mus., Cat. Nos. 69747, 60748.
5. (X2.) Exterior of a broken dorsal valve. U. S. Nat. Mus.,
Cat. No. 60749.

The specimens represented by figs. 3-5 are from locality 360a,
Ozarkian: Manitou formation; red silicious limestone, Beyer Park,
El Paso County, Colorado.

a sO WOOLEY NVAICOU. 2-8 ccn ons « a case keen he ne cee cadet cer 514
Fics. 6, 6a. (X3.) Top and side view of a cast of the interior of a
broken ventral valve. U. S. Nat. Mus., Cat. Nos. 69750.
7. (X3.) Portion of the radially striated surface of the interior
of the shell. U. S. Nat. Mus., Cat. No. 69751.
8, 8a. (X3.) Top and side views of a cast of a ventral valve.
U. S. Nat. Mus., Cat. No. 69752.

The specimens represented by figs. 6-8a are from locality 73¢c,
Upper Cambrian: Muav formation; Hermit Creek, Grand Canyon
of the Colorado River, Arizona.

Eoorthis putillus Walcott (see pl. 114, figs. 6, 7).......0..ecceceeceeceee 510
Fic. 9. (X 3.) Group of shells in shaly limestone [from a locality
? miles (?km.) distant from locality 61q at Mount Robson].
U. S. Nat. Mus., Cat. No. 69753.

The specimen represented by fig. 9 is from locality 67w, Ozarkian:
Mons formation; Sawback Range, Alberta, Can.

544. SMITHSONIAN MISCELLANEOUS COLLECTIONS — VOL. 67
DESCRIPTION OF PLATE 116
PAGE
Eoorthis wichttaensts Walcott. \o. 2. oi. .'2 02-2 + e,5 0 se ene eee 513
Fic. 1. (X4.) Exterior of ventral valve. U. S. Nat. Mus., Cat. No.
69754.
2. (X4.) Partially exfoliated ventral valve. U. S. Nat. Mus.,
Cat. No. 60755.
3. (X4.) Interior of a ventral valve showing strong vascular
sinuses. U. S. Nat. Mus., Cat. No. 69758.
4. (xX 4.) Exfoliated ventral valve doubtfully referred to this
species. U. S. Nat. Mus., Cat. No. 69750.
5. (X4.) Dorsal valve. U. S. Nat. Mus., Cat. No. 69760.
6. (XX 4.) Ventral valve on same surface of limestone as fig. 5.
U.S. Nat. Mus., Cat. No. 69761.
7. (X4.) Exterior of a dorsal valve. U.S. Nat. Muss Gata:
69762.
8. (xX 4.) A partially exfoliated dorsal valve. U. S. Nat. Mus., Cat.
No. 69756.
9. (XX 4.) Outer surface of a dorsal valve. U. S. Nat. Mus., Cat.
No. 60757.
10. (x 8.) Enlargement of surface to show main ribs. intercalated

finer ribs or elevated striz, and concentric lines and striae _

of growth. U. S. Nat. Mus., Cat. No. 69763.

The specimens represented by figs. 1, 2, 8 and 9 are from locality
641, Upper Cambrian: Lyell formation. Head of Glacier Lake Can-
yon, Alberta, Canada.

Figs. 3-7 and 10 are from locality 64t, Lyell formation, Sawback
Range, Alberta, Can.

EOORTHIS.

eee
PO NY TA tty em ARO, ee PUREE CCITT, SEH NTS SIE
TAR IE Heme SR ~
* WS on EET EL THEE POE RT oe ae ee Oe ee w4
. see tite Me $ ‘ pnts".
Feet er Ree ten ' Oa,

Das

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9, PL. 117

EOORTHIS-SYNTROPHIA.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 545

DESCRIPTION OF PLATE 117

OE MEESTER CGN VV AICOLE wn, ree sib ke ects Ps ac wtekivtosler dee ae vipa fee apes
Fics. 1, Ia, and 2, 2a. Top and side views of ventral valves from
locality 14k, Upper Cambrian limestone on Wolf Creek, 15
miles (24.2 km.) west-southwest of Sheridan, Sheridan
County, Wyoming. U. S. Nat. Mus., Cat. Nos. 52320a and
52320b, respectively.
3 and 4. Exterior of dorsal valves associated with the dorsal
valves represented by figures 1 and 2. U. S. Nat. Mus., Cat.
Nos. 52320c and 52320d, respectively.
5and6. Exterior of small ventral valves. U. S. Nat. Mus., Cat.
Nos. 52319a and 523I0b, respectively.
7. Exterior and side view of a ventral valve. U. S. Nat. Mus.,
Cat. No. 52310c.
7a. Side view of a young, convex shell. U. S. Nat. Mus., Cat. No.
52310d.
8. Posterior portion of the interior of an abraded ventral valve.
U. S. Nat. Mus., Cat. No. 52310e.
9. Interior of an abraded dorsal valve. U. S. Nat. Mus., Cat. No.
52310f.

The specimens represented by figures 5-9 are from locality 168,
Middle Cambrian limestones, Tepee Creek, Bighorn Mountains,
Wyoming.

Figs, I to 9, inclusive, are the same as figs. Ii to 17, pl. 96, of Mong.
51, U. S. Geological Survey, 1912.

neem eaaE UIE ViNI CQ Ett Sens toe 5. kde cick a's Sarsiore Siete w'n dle os, ofa vUlvisieieinle a
Fics. 10 and 11. (X3.) Ventral valves with very regular radiating
elevated lines and fine strong ribs. U. S. Nat. Mus., Cat.
Nos. 69764, 69765.
12, ( 3.) A large dorsal valve with the main radiation ribs broken
off. The smaller associated shells have very strong radiating
ribs. U. S. Nat. Mus., Cat. No. 69766.
13. (X3.) A ventral valve with the apex broken down. U. S. Nat.
Mus., Cat. No. 69767.

The specimens represented by figs. 10-13 are from locality 16u,
Ozarkian: Mons formation, Sinclair Canyon, B. C., Can.

MOTE eis NV AICOPC: bt2 as ota laclc eu ce din nla dew ee ans iGRoe Coto eeee
Fic. 14. (X 4.) A ventral valve with a strong mesial sinus. U. S. Nat.
Mus., Cat. No. 69768.
15. (X4.) Two ventral valves that vary slightly in outline. U. S.
Nat. Mus., Cat. No. 69760.
nes § (COX +) Dorsal valve. U. S. Nat. Mus., Cat. No. 69770.
17, (X4.) A young shell with a very slight mesial fold. U. S.
Nat. Mus., Cat. No. 69770.

The specimens represented by figs. 15-17 are from locality 65f,
Ozarkian: Mons formation, Glacier Lake, Alberta, Can.

509

517

546 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PEAT Hams

Syntropihia perilla Walcott... 20. 225 sch.vtse bom wa nie cee crete eee 519
Fic. 1. (X 4.) Ventral valve with traces of radiating lines on the inner
layers of the shell. U. S. Nat. Mus., Cat. No. 69773.
2. (X4.) A larger, more transverse ventral valve with shell partly
exfoliated. U. S. Nat. Mus., Cat. No. 69772.
3. (X<4.) A large dorsal valve. U. S. Nat. Mus., Cat. No. 69774.
4. (>4.) An elongate dorsal valve. U. S. Nat. Mus., Cat. No.
60775.
(X 4.) Dorsal valve. U. S. Nat. Mus., Cat. No. 69776.
(X< 4.) Ventral valve, U. S. Nat. Mus., Cat. No. 69777.
7. (X4.) A small dorsal valve. U. S. Nat. Mus., Cat. No. 69778.

oye

The specimens represented by figs. 1-7, with the exception of fig. 2,
are from locality 65x, Ozarkian: Mons formation, Clearwater
Canyon, Alberta, Can.

Fig. 2 is from Fossil Mountain, Alberta, Can.

Huenella:srmon, Wealc0tt. incos vena ccs On eed cies 1 ee 521
Fic. 8. (XX 4.) A ventral valve with a broad shallow mesial sinus.
U. S. Nat. Mus., Cat. No. 69779.
9. (xX 8.) Enlargement of surface ribs of fig. 8.

The specimen represented by figs. 8 and 9 is from locality 64z,
Ozarkian: Mons formation; Sawback Range, Alberta, Can.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9, PL, 118

SYNTROPHIA-~HUENELLA,

VOL. 67, NO. 9, PL. 119

SMITHSONIAN MISCELLANEOUS COLLECTIONS

SYNTROPHIA-HUENELLA,

Fic. 14. (x 4.) Enlargement of surface to show strong, fine radiating
ribs. U. S. Nat. Mus., Cat. No. 60793.

The specimens represented by figs. 11-14 are from locality 65e,
Ozarkian: Mons formation; Sawback Range, Alberta, Can.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 547
DESCRIPTION OF PLATE 119
PAGE
MEME SNEAMIIESE SE ANN TNCIOU ES Pie Pe cer szieda Mistanele ya cae dasa cba as"e.9. ¢.0'0)d 4 Dioleis crete 517
Fic. 1. (XX 4.) Ventral valve with strong ridge on sides of mesial
fold. U. S. Nat. Mus., Cat. No. 60780.
2. (X 4.) Dorsal valve with furrow on mesial fold. U. S. Nat.
Mus., Cat. No. 69781.
3. (X 4.) Dorsal valve with faint furrow on mesial fold. U. S.
Nat. Mus., Cat. No. 69782.
The specimens represented by figs. 1-3 are from locality 660,
Ozarkian: Mons formation; Fossil Mountain, Alberta, Can.
RI MEA Rae ESET CISC IV ANC OUTS cca sociciy olvisle nin wks di siciele diols go a eb ale dw ale oe welders 518
Fic. 4. (X 4.) Ventral valve with a slight mesial sinus. U. S. Nat.
Mus., Cat. No. 69783.
5. (X4.) Dorsal valve with broad mesial fold. U. S. Nat. Mus.,
Cat. No. 69784.
6. (X 4.) Dorsal valve with a more sharply elevated mesial fold.
U. S. Nat. Mus., Cat. No. 609785.
7. (X4.) Dorsal valve with a few faint radiating ribs. U. S. Nat.
Mus., Cat. No. 69786.
8 (X4.) Ventral valve. U. S. Nat. Mus., Cat. No. 69787.
9. (xX 4.) A large exfoliated ventral valve preserving traces of the
vascular sinuses. U. S. Nat. Mus., Cat. No. 69788.
The specimens represented by figs. 4-7 are from locality 66 0, given
under S. nisis above. Figs. 8 and 9 are from the same locality, but a
little lower in the section (66n).
PINE ECOL Gee ate. G,c2e Glades Siege Saaisic be ea salccceecbessenes 520
Fic. 10. (> 4.) Interior of a ventral valve showing cast of pseudo-
spondilium. U.S. Nat. Mus., Cat. No. 69780.
The specimen represented by fig. 10 is from locality 64w, Upper
Cambrian: Lyell formation; Sawback Range, Alberta, Can.
Derr TIRER IUD INCI CCUER gid oy oe Se tiara Gaia @ crcl esas sie ow die tie she eeaeeccce 521
Fie. 11. (xX 4.) Exterior of a broken dorsal valve. U. S. Nat. Mus.,
Cat. No. 69790.
12. (X4.) Cast of interior of a ventral valve showing cast of
pseudospondilium. U. S. Nat. Mus., Cat. No. 69701.
13. (X4.) Ventral valve with a broad mesial sinus. U. S. Nat.
Mus., Cat. No. 69702.
Boonies nophow Walcott (see pl: 114) fies. T-5))oo..c0.05 seen ece ces nae 508

548 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 120

Huenella: tcetasy Walcott): cc. nce © oe Cem ace een 6 ante ee eee
Fic. 1. (X4.) Ventral valve. U. S. Nat. Mus., Cat. No. 69794.
2. (XX 4.) Exterior surface of a small ventral valve. U. S. Nat.
Mus., Cat. No. 69795.
3. (X4.) A dorsal valve associated with fig. 1. U. S. Nat. Mus.,
Cat. No. 60796.

The specimens represented by figs. 1-3 are from locality 65¢,
Ozarkian: Mons formation: Sawback Range, Alberta, Can.

Huyenella* temana Walcottys.).. cc wac ce og cine ee oe ek ee eee 522

Fic. 4. (X 4.) A ventral valve partially concealed by the mesial sinus
of another specimen.
6. (x 4.) Interior of a ventral valve that occurs on the same
weather surface as 4 and 8.
(xX 4.) Dorsal valve associated with Huenella weedi Walcott.

7
8. (x 4.) Part of a small piece of a thin layer of limestone on
which the fossils weather out in relief. Both H. terana and
H. weedi occur scattered irregularly over the surface.
U. S. Nat. Mus., Cat. No. 69797.
Hueneila weed¢ WW alcotts ce os eas te eo eee eee PRS... wi 22

Fic. 5. (xX 4.) A small portion of the outer surface of the shell.

7x4.) Dorsalivalve:
8 (X<4.) Ventral valve associated with H. terana Walcott.

U. S. Nat. Mus., Cat. No. 69708.

The specimens represented by figs. 4-8 are from locality 302g,
Upper Cambrian; Crowfoot Ridge, Yellowstone National Park,
Wyoming.

SMITHSONIAN MISCELLANEOUS COLLECTIONS : 7 NO] 9 PES 420

HUENELLA,

SMITHSONIAN MISCELLANEOUS COLLECTIONS

Pi af

BILLINGSELLA-OBOLUS.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 549

DESCRIPTION OF PLATE 121

SCL UONAGEI NN MCOEL Serna vac sere e aiiia ys, Hade’atbe nile sn « SMe Moraine vla'e d ata0 503
Fic. 1. (X4.) Exfoliated dorsal valve. U. S. Nat. Mus., Cat. No.
19809.
2. (X4.) An exfoliated dorsal valve showing traces of muscle
scars. U. S. Nat. Mus., Cat. No. 69807.
3. (X4.) Natural cast of interior of ventral valve showing
visceral area and main vascular sinuses. U. S. Nat. Mus.,

Cat. No. 69808.

The specimens represented by figs. 1-3 are from locality 17t, Ozark-
ian: Mons formation, Sabine Mountain, B. C., Can.

Preece meee SPIT ORE NY AIC OEE Se SAN). aici ts cio ree 3a 00d Sek oom isle’ o dec dea gee ees ve 487
Fic. 4. (X3.) A small well preserved dorsal valve. U. S. Nat. Mus.,
Cat. No. 60810.
5. (X3.) A partially exfoliated ventral valve. U. S. Nat. Mus.,
Cat. No. 609812.
6. (X3.) A ventral valve with some of the inner layers of the
shell preserved. U.S. Nat. Mus., Cat. No. 69811.
7. (X3.) Three dorsal valves and a broken ventral valve as they
occur on the surface of shaly limestone. U. S. Nat. Mus.,
Cat. No. 69813.

The specimens represented by figs. 4-7 are from locality 68c, Lower
Cambrian: Mt. Whyte formation, Mount Whymper, B. C., Can.

EPEC UT CSL OMMT ) MOLIETES WV AICOLES « cic og ccniisct vl wleces Seis ceacecnsses 487
Fic..8. (Xx 3.) A flattened ventral valve with the apex broken off. U. S.
Nat. Mus., Cat. No. 60814.
9. (X3.) A flattened, slightly distorted dorsal valve showing the
elevated transverse lines. U. S. Nat. Mus., Cat. No. 69815.
10. (X3.) A partially exfoliated dorsal valve. U. S. Nat. Mus.,
Cat. No. 60816.

The specimens represented by figs. 8-10 are from locality Itc,
Upper Cambrian: Hardystone Quartzite, Newton, New Jersey.

550 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION (OF PLATE 122

PAGE
Lingulella. mailiont Walcott. >. 55.0 seh jecela dastkdeetes oe eee ee 492
Fic. 1. (X 4.) Broad form of ventral valve. U. S. Nat. Mus., Cat. No.
60818.
2. (X4.) An elongate dorsal valve. U. S. Nat. Mus., Cat. No.
60810.

3. (X4.) Narrow elongate form of ventral valve. U. S. Nat.
Mus., Cat. No. 69820.

4. (X 4.) Broad form of dorsal valve. U. S. Nat. Mus., Cat. No.
69821.

The specimens represented by figs. 1-4 are from locality 61u, Ozark-
ian: Chushina formation, Mount Robson, B. C., Can.

Linguiella waptaewsts:. Walcott.cs seen ee eee eee eee 496
Fic. 5. (X6.) Dorsal valve with a flattened ventral valve turned
sideways beneath it. U. S. Nat. Mus., Cat. No. 69822.
6. (X6.) An uncompressed ventral valve. U. S. Nat. Mus,
Cat. No. 69823.
(X 6.) A group of ventral and dorsal valves on a piece of hard
silicious shale. U. S. Nat. Mus., Cat. No. 69824.
8. (Xx 6.) Ventral valves on the same piece of shale as those
represented by fig. 7. U. S. Nat. Mus., Cat. No. 69824.

The specimens represented by figs. 5-8 are from locality 35k, Mid-
dle Cambrian: Burgess shale. Ridge between Mount Wapta and
Mount Field, B. C., Can.

Acrothyra gregaria Walcott «i. .c% ws Sat bce bcs oe baie srenioe Be eee 498
Fic. 9. (X8.) Partially exfoliated ventral valve showing cast of

apical callosity and main vascular sinuses. U. S. Nat. Mus.,
Cat. No. 60825.

1o. (X8.) Partially exfoliated dorsal valve showing trace of
median septum. U.S. Nat. Mus., Cat. No. 69826.

11, (x 8.) Exterior of a dorsal valve. U. S. Nat. Mus., Cat. No.
69827.

12. (X8.) A group of shells on a piece of hard silicious shale.
U. S. Nat. Mus., Cat. No. 69828.

The specimens represented by figs. 9-12 are from locality 35k as
above.

VOL. 67, NO. 9, PL. 122

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LINGULELLA-BILLINGSELLA.
Novaya Zemlaya Brachiopods.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 551
DESCRIPTION OF PLATE 123
PAGE
MTEC GUN AIGOLU sc occince piacevy Chix ts melee e cible © ie aq.sis ele ie seis eee wet 524
Fic. 1. (X 3.) An exfoliated ventral valve.
2. (X3.) A partially exfoliated dorsal valve.
POSER CULO GI n de MIACKIANL ONY AICOUL: oo. occ ce nse oe ois a sc ebce uss ca acetas hers 524
Fics. 3 and 4. (X 6.) Dorsal valves.
5. (X6.) Ventral valve.
Pea MtecIIs NW AICOLL. 5.55 < six ties. v's sie d'or Sia ws oa oe ec cies san eces 525
Fic. 6. (X2.) View of a partially exfoliated ventral valve, preserving
part of main vascular sinuses and inner markings of shell.
7. (X2.) Partial interior of a dorsal valve. See fig. 15.
8 (xX 2.) Partly exfoliated dorsal valve.
9. (X2.) Partly exfoliated ventral valve.
10. (X2.) Dorsal valve with a shallow median furrow.
Il. (X2.) Dorsal valve with outer surface layer exfoliated.
12. (X3.) Top view of a small ventral valve.
13. (X2.) Dorsal valve with outer surface preserved.
14. (X2.) Exterior of ventral valve with outer surface layer more
or less exfoliated.
15. (X2.) Partially exfoliated dorsal valve. See fig. 7.
16. (XX 4.) Partialy exfoliated ventral valve showing cast of vas-

cular sinuses and umbonal cavity.

The specimens represented by figs. 1, 2, 6-16, are from locality 67y,
Island of Novaya Zemlya, Russia, west coast of southern island,
Gribovii Fjord.

Figs. 3, 4, 5 are from locality 68a, west coast of southern island in
mountains 7 km. northwest of the head of Bessimyanni Fjord.

552 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67

DESCRIPTION OF PLATE 124

Billnigsella .? -appius: Walcott. 0.00% a. wee ce oie oe ee oe ee 525
Fic. 1. (X2.) Exterior of dorsal valve.

2. (X2.) Exterior of ventral valve with shell crushed into um-
bonal cavity.

3. (X4.) Exterior of a small dorsal valve that may belong with
this species.

4 and 6. (X 2.) Casts of interior of ventral valves.

5. (X2.) Exfoliated ventral valve doubtfully referred to this
species.

7. (X2.) Exterior surface of dorsal valve.

8. (xX 2.) Top and side view of exterior of a ventral valve.

The specimens represented by figs. 1-8 are from locality 67y,
Island of Novaya Zemlya, Russia, west coast of southern island,
Gribovii Fjord.

Eoortus sdbus Walcott:2..2ced.008 065s dence oe ee eee 526
Fic. 9. (x 4.) Cast of interior of a small ventral valve.

10. (X3.) Top view of exterior of a ventral valve.

Ir. (X3.) Natural cast of the interior of a dorsal valve.

12. (X2.) View of the cast of a ventral valve.

13. (X3.) Partly exfoliated dorsal valve having a shallow mesial
sinus.

14. (X3.) One of a small group of shells in an arenaceous
matrix.

15. (X4.) Fragment of a cast of the exterior surface.

The specimens represented by figs. 9-14 are from locality 68a, west
coast of southern island, mountains 7 km. northwest of the head of
Bessimyanni Fjord. Fig. 15 is from locality 67y, west coast of
southern island, Gribovii Fjord, Island of Novaya Zemlya, Russia.

VOL. 67, NO. 9, PL. 124

SMITHSONIAN MISCELLANEOUS COLLECTIONS

EOORTHIS.

Novaya Zemlaya Brachiopods.

BILLINGSELLA

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9, PE. 125

15
HUENELLA.
Novaya Zemlaya Brachlopods.

NO. 9 CAMBRIAN AND OZARKIAN BRACHIOPODA 553
DESCRIPTION OF PLATE 125

PAGE

ET MERICIID TIAA MANCO Es ot. cisls taeda Be Ger vie 6 «ci chade Sele sale ee ed 6 wlns 526

Fic. 1. (X3.) Exterior of a ventral valve with one well defined mesial

plication in furrow.

2, 3, 4. (X3.) Top, side and back views of cast of the interior
of a ventral valve showing pseudospondilium of medium
length, short slight sinuses extending out into the cardinal
slopes.

5, 6. (X3.) Top and half back view of cast of interior of ventral
valve with a narrow, long pseudospondilium, base of short
vascular sinuses, and two plications in mesial sinus.

(X 3.) Cast of the interior of a ventral valve with two strong
and one faint plications in mesial furrow, and a relatively
short pseudospondilium.

8,9. (xX 3.) Top and front views of a cast of interior of a dorsal
valve showing imprint of adductor muscle scars, small
pseudospondilium and a minute cardinal process.

10, II, 12, 13. (X3.) Top, front and side views of casts of interior

of dorsal valves varying somewhat from figs. 8, 9.

14, 15. (X3.) Top and side view of exterior of dorsal valve with

three plications on a rather mesial fold.

The specimens represented by figs. 1-15 are from locality 68a,
mountains 7 km. northwest of the head of Bessimyanni Fjord, island
of Novaya Zemlya, Russia.

554 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

DESCRIPTION OF PLATE 126

Zomia luca Wal cottiasscc elcome eirat oer RRO CE CR eee ee era
Fic. 1. (XX 3.) Natural cast of the interior of one side of the carapace
of a large specimen. U. S. Nat. Mus., Cat. No. 69709.
2. (X3.) Natural cast of a smaller carapace. U. S. Nat. Mus.,
Cat. No. 69800.
3, 3a. (X3.) Side and anterior view of a cast preserving the
impression of both sides of the carapace. U. S. Nat. Mus.,
Cat. No. 69801.

The specimens represented by figs. 1-3, and 3a, are from locality
66n, Ozarkian: Mons formation, Fossil Mountain, Alberta, Can.

Eudoceras a2) sntonsensts NV alcott.c cei een eee eee eee
Fic. 4. (x 4.) View of the deeper side of the conch in which the annu-
lations and the lines of the camerz are clearly defined.
U. S. Nat. Mus., Cat. No. 69802.
4a. (X4.) Dorsal or ventral view of fig. 4 specimen.
4b. (X4.) Section of fig. 4 specimen, showing the oval dorso-
ventral section.

The specimens represented by figs. 4, 4a, 4b, are from locality Sap,
Ozarkian: Mons formation, Glacier Lake Canyon Valley, Alberta,

Can.

Ellesmeroceras joosonensise NVialcOtts one aes ccs oe eee eee eee
Fics. 5 and 6. ( 4.) Two views of a fragment of a conch preserving
a portion of the living chamber and a number of the sutures
separating the septa. U. S. Nat. Mus., Cat. No. 69803.
7, 7a. (X4.) A fragment of a conch preserving a portion of the
living chamber, a few septa, and at the end one of the

camera with a section of the siphuncle. U. S. Nat. Mus.,

Cat. No. 69804.

8. (X 4.) Ventral side of a broken conch preserving the living
chamber, septa and sutures; the siphuncle shows fairly well.
U. S. Nat. Mus., Cat. No. 69805.

9, 9a. (X4.) A finely dissected specimen of the septate middle
section of a conch showing the septa of the siphuncle with
slightly elevated margin on the sutures, the camerz, and
sutures. Fig. 9a illustrates the position of the siphuncle.

U. S. Nat. Mus., Cat. No. 69806.

The specimens represented by figs. 5-9a are from locality 614q,
Ozarkian: Chushina formation, Billings Butte, Mount Robson
District, B. C., Gan.

529

527

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 9, PL. 126

OZOMIA-ENDOCERAS-ELLESMEROCERAS.

ITH IAN INSTITUTION LI

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WALMLUUNAN
908 89

8 01421 45

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